☐ This post-effective amendment designates a new effective date for a previously filed post-effective amendment.

This Statement of Additional Information is not a prospectus but should be read in conjunction with the Funds’ “Thornburg Funds” Prospectus dated February 1, 2024 (the “Prospectus”). A copy of the Prospectus and the most recent Annual and Semi-Annual Reports for each of the Funds may be obtained at no charge by going to “Forms and Literature” on the Thornburg website at www.thornburg.com and clicking the appropriate hyperlink to view the current Prospectus or Financial Reports, by telephoning a Fund Support Representative at 1-800-847-0200, or by writing to the distributor of the Funds’ shares, Thornburg Securities LLC, at 2300 North Ridgetop Road, Santa Fe, New Mexico 87506. The audited financial statements contained in the Annual Reports to Shareholders for each of the Funds for the fiscal year ended September 30, 2023 are incorporated herein by reference. No financial statements are available for the Core Plus Bond Fund because the Fund commenced investment operations as of October 2, 2023. This Statement of Additional Information is incorporated by reference into the Prospectus.

The description of investment policies and limitations that appears in this Statement of Additional Information and the Prospectus does not impose a contractual duty on the Funds or their investment advisor to comply with those policies and limitations, and no express or implied contract is created among a Fund and its shareholders by virtue of those shareholders having made an investment in the Fund or having received this Statement of Additional Information or the Prospectus. Furthermore, while the Trust may enter into contracts with third parties to manage the Funds’ assets and provide other services, as described in this Statement of Additional Information and the Prospectus, the Trust and each such third party are the sole intended beneficiaries of those contracts, and the Funds’ shareholders are not third party beneficiaries of those contracts.

Global Opportunities Fund, International Equity Fund, Better World International Fund, International Growth Fund, Developing World Fund, Small/Mid Cap Core Fund, Small/Mid Cap Growth Fund, Investment Income Builder Fund, Summit Fund, Ultra Short Income Fund, Limited Term U.S. Government Fund, Limited Term Income Fund, Core Plus Bond Fund, Strategic Income Fund, Short Duration Municipal Fund, Limited Term Municipal Fund, Limited Term California Fund, Intermediate Municipal Fund, and Strategic Municipal Income Fund are diversified series, and Intermediate New Mexico Fund and Intermediate New York Fund are nondiversified series, of Thornburg Investment Trust, a Massachusetts business trust (the “Trust”) organized on June 3, 1987 as a diversified, open-end management investment company under a Declaration of Trust (the “Declaration”). The Trust currently has 24 active Funds, 21 of which are the subject of this Statement of Additional Information. The Trustees are authorized to divide the Trust’s shares into additional series and classes.

The assets received for the issue or sale of shares of each Fund and all income, earnings, profits, and proceeds thereof, subject only to the rights of creditors, are specifically allocated to the Fund, and constitute the underlying assets of that Fund. The underlying assets of each Fund are segregated on the books of account, and are charged with the liabilities with respect to that Fund and with a share of the general expense of the Trust. Expenses with respect to the Trust are allocated in proportion to the asset value of the respective series and classes of the Trust except where allocations of direct expense can otherwise be fairly made. The officers of the Trust, subject to the general supervision of the Trustees, determine which expenses are allocable to a given Fund, or generally allocable to all of the series of the Trust (the “Funds”). In the event of the dissolution or liquidation of the Trust, shareholders of each Fund are entitled to receive as a class the underlying assets of that Fund which are available for distribution.

Each of the Funds may in the future, rather than invest in securities generally, seek to achieve its investment objective(s) by pooling its assets with assets of other funds for investment in another investment company having the same investment objective(s) and substantially similar investment policies and restrictions as the Fund. The purpose of such an arrangement is to achieve greater operational efficiencies and to reduce cost. It is expected that any such investment company would be managed by Thornburg Investment Management, Inc. (“Thornburg”) in a manner substantially similar to the corresponding Fund. Shareholders of each Fund would receive prior written notice of any such investment, but may not be entitled to vote on the action. Such an investment would be made only if at least a majority of the Trustees of the Fund determined it to be in the best interest of the participating Fund and its shareholders.

The Trust is an entity of the type commonly known as a “Massachusetts business trust.” Under Massachusetts law, shareholders of such a trust may, under certain circumstances, be held personally liable for the obligations of the trust. The Declaration of Trust provides that the Trust shall not have any claim against shareholders except for the payment of the purchase price of shares. However, the risk of a shareholder incurring financial loss on account of shareholder liability is limited to circumstances in which a Fund itself would be unable to meet its obligations. Thornburg believes that, in view of the above, the risk of personal liability to shareholders is remote.

Each Fund may hold special shareholder meetings and transmit proxy materials. These meetings may be called to elect or remove Trustees, change fundamental investment policies, or for other purposes. Shareholders not attending these meetings are encouraged to vote by proxy. Each Fund will transmit proxy materials in advance, including a voting card and information about the proposals to be voted on. The number of votes you are entitled to is based upon the number of shares you own. Shares do not have cumulative rights or preemptive rights.

State Street Bank and Trust Company, Boston, Massachusetts, is custodian of the assets of the Funds. The Custodian is responsible for the safekeeping of the Funds’ assets and the appointment of subcustodian banks and clearing agencies. The Custodian takes no part in determining the investment policies of the Funds or in deciding which securities are purchased or sold by the Funds.

Information about each Fund’s principal investment strategies and the principal risks associated with those investment strategies is provided in the Prospectus. A “principal investment strategy” of a Fund is a strategy which Thornburg anticipates may be important in pursuing the investment objective(s) stated in the Fund’s prospectus and which Thornburg anticipates may have a significant effect on the Fund’s performance. In general, a security or investment strategy will not be considered a principal strategy of a Fund if it will not represent more than ten percent of a Fund’s assets.

The following discussion supplements the information in the Prospectus by providing additional detail about some of the investments that a Fund is generally permitted, but not required, to make in pursuing the Fund’s investment objective(s) and certain risks associated with those investments or to which a Fund may otherwise be subject. Not all of the investments identified below will be used by each Fund, and some investments that may be used by a Fund would not ordinarily be considered a principal investment strategy of the Fund. In general, a Fund may make any investment, including investments which are not identified below, if the investment advisor reasonably believes that the investment is consistent with the Fund’s investment objective(s) and policies and the Fund’s investment limitations do not expressly prohibit the Fund from doing so.

Under certain circumstances, a Fund is only permitted to invest a certain percentage of its assets in a particular investment strategy. For more information about the specific investment limitations that may be applicable to a Fund, please refer to the Prospectus and to the “Investment Limitations” section of this Statement of Additional Information. For purposes of any such limitation on the percentage of a Fund’s assets that could be invested in a particular investment strategy, the term “assets” means net assets of the Fund (determined immediately after and as a result of the Fund’s acquisition of a given investment) plus the amount of borrowings for investment purposes.

Global Opportunities Fund, International Equity Fund, Better World International Fund, International Growth Fund, Developing World Fund, Small/Mid Cap Core Fund, Small/Mid Cap Growth Fund, and Investment Income Builder Fund are sometimes referred to collectively in this Statement of Additional Information as the “Equity Funds.” Short Duration Municipal Fund, Limited Term Municipal Fund, Intermediate Municipal Fund, Strategic Municipal Income Fund, Limited Term California Fund, Intermediate New Mexico Fund and Intermediate New York Fund are sometimes referred to collectively in this Statement of Additional Information as the “Municipal Funds.” Together with the Municipal Funds, Limited Term U.S. Government Fund, Ultra Short Income Fund, Limited Term Income Fund, Core Plus Bond Fund, and Strategic Income Fund are sometimes referred to collectively in this Statement of Additional Information as the “Fixed Income Funds.” The Summit Fund is characterized by Thornburg as a “Multi-Asset Fund.”

Bonds and other debt obligations are used by issuers to borrow money from investors. The issuer pays the investor a fixed or variable rate of interest, and must repay the amount borrowed at maturity. The values and yields of debt obligations are dependent upon a variety of factors, including the condition of the general market, general market interest rates, the size of a particular debt offering, the maturity of the debt obligations, and the creditworthiness and rating of the issuer. Variations in the value of a debt obligation held in the Fund’s portfolio arising from these or other factors will cause changes in the net asset value of the Fund’s shares.

The following discussion contains additional detail about debt obligations, including some of the specific types of debt obligations in which a Fund may invest and certain risks associated with those investments. You should read the Prospectus for more information about the characteristics and risks of debt obligations. You should also read “Investing in Foreign Debt Obligations and Foreign Equity Securities” below for information about some of the characteristics and risks of foreign debt obligations.

Many bonds and other debt obligations are assigned credit ratings by ratings agencies such as Moody’s Investors Service (“Moody’s”) or S&P Global Ratings (“S&P”). The ratings of Moody’s and S&P represent their current opinions as to the creditworthiness of the issuers of the debt obligations which the ratings agencies undertake to rate. In determining credit ratings, ratings agencies evaluate each issuer’s capacity and willingness to meet its financial commitments as they come due, and may assess terms, such as collateral security and subordination, which could affect payment in the event of the issuer’s default.

While credit ratings may be helpful in evaluating the safety of principal and interest payments under debt obligations, credit ratings do not reflect the risk that market values of debt obligations will fluctuate with changes in interest rates, general economic trends or other factors. Accordingly, even the highest rated debt obligation may experience wide price movements. Credit rating agencies may also fail to change credit ratings in a timely fashion to reflect events occurring subsequent to the initial ratings. Furthermore, it should be emphasized that credit ratings are general and are not absolute standards of quality. Debt obligations with the same maturity, coupon and rating may have different yields, while debt obligations of the same maturity and coupon with different ratings may have the same yield.

In addition to using information provided by ratings agencies, Thornburg will subject each debt obligation under consideration for investment to its own credit analysis in an effort to assess each issuer’s financial soundness. This analysis is performed by Thornburg for a particular debt obligation at the time that a Fund purchases that obligation and will be reviewed by Thornburg from time to time thereafter.

Each ratings agency uses its own rating classification system to indicate the credit rating assigned to a particular debt obligation. In general, the ratings agencies classify debt obligations into two categories for purposes of the ratings process – long term and short term. The ratings agencies typically assign short term ratings to debt obligations that are considered short term in the relevant market. In the United States, for example, the ratings agencies deem short term debt obligations to include commercial paper and other obligations with an original maturity of no more than 365 days. The following is a brief description of the applicable ratings symbols and their meanings for each of Moody’s and S&P.

Moody’s may append the numerical modifiers 1, 2 or 3 to any debt obligation rated Aa through Caa to indicate the relative standing of that obligation within its principal rating category. Similarly, S&P may append a “+” or “-” to any debt obligation rated AA through CCC to indicate the relative standing of that obligation within its principal rating category. The foregoing ratings are sometimes presented in parentheses preceded with “Con.” (Moody’s) or “p” (S&P), indicating that the obligations are rated conditionally/provisionally. Bonds for which the security depends upon the completion of some act or the fulfillment of some condition may be rated in this fashion. The parenthetical rating denotes the probable credit status upon completion of construction or elimination of the basis of the condition.

Ratings of Municipal Notes. In addition to the foregoing, the ratings agencies may separately categorize municipal notes. Municipal notes are debt obligations issued by states, cities and local authorities and which mature in one year or less. When rating municipal notes, Moody’s uses ratings symbols MIG 1, MIG 2, MIG 3, MIG 4 and SG, and S&P uses ratings symbols SP-1+, SP-1, SP-2 and SP-3. As with the ratings systems used for other debt obligations, the rating agencies’ categorization of municipal notes reflects a decreasing judgment of the ability of the issuer to meet its financial obligations under the note.

Dual Ratings. The rating agencies may assign dual ratings to all long term debt obligations that have a demand or multiple redemption feature. The first rating addresses the likelihood of repayment of principal and interest as due and the second rating addresses only the demand feature. The long term debt rating symbols are used to denote the long term maturity and the short term debt rating symbols are used to denote the put option (for example, “AAA/A-1+”). For certain “demand notes” maturing in 3 years or less, the respective municipal note rating symbols, combined with the short term debt obligation symbols, are used (for example. “SP-1/A-1”).

As discussed in the Prospectus, several of the Fixed Income Funds seek to reduce changes in the value of their shares by maintaining a portfolio of investments with a certain dollar-weighted average maturity. A debt obligation’s maturity generally represents the time remaining until the principal amount of that obligation becomes due and payable.

For purposes of determining an investment’s maturity, Thornburg will treat a debt obligation as having a maturity earlier than its stated maturity date if the instrument has technical features (such as put or demand features) or a variable rate of interest which, in the judgment of Thornburg, will result in the instrument being valued in the market as though it has an earlier maturity.

In addition, each Fund may estimate the expected maturities of certain securities it purchases in connection with achieving its investment objectives. Certain obligations, such as United States Treasury Bills and United States Treasury Notes, have stated maturities. However, other obligations a Fund may acquire are interests in pools of mortgages or other loans having varying maturities. Due to prepayments of the underlying mortgage instruments or other loans, such securities do not have a known actual maturity (the stated maturity date of collateralized mortgage obligations is, in effect, the maximum maturity date). In order to determine whether such a security is a suitable and permissible investment for a Fund (and assuming the security otherwise qualifies for purchase by the Fund), the security’s remaining term will be deemed equivalent to the estimated average life of the underlying mortgages at the time of purchase of the security by the Fund. Average life will be estimated by a Fund based on Thornburg’s evaluation of likely prepayment rates after taking into account current interest rates, current conditions in the relevant housing markets and such other factors as it deems appropriate. There can be no assurance that the average life as estimated will be the actual average life. For example, the mortgage instruments in the pools underlying mortgage-backed securities may have a range of different original maturities. The average life of such a security at the time of purchase by a Fund is likely to be substantially less than the maximum original maturity of the mortgage instruments underlying the security because of prepayments of the mortgage instruments, the passage of time from the issuance of the

security until its purchase by a Fund and, in some cases, the wide dispersion of the original maturity dates of the underlying mortgage instruments.

Certain securities which have variable or floating interest rates or demand or put features may be deemed by Thornburg to have remaining actual lives which are less than their stated nominal lives. In addition, certain asset-backed securities which have variable or floating interest rates may be deemed by Thornburg to have remaining lives which are less than the stated maturity dates of the underlying mortgages.

Ultra Short Income Fund seeks to reduce changes in the value of its shares by maintaining a portfolio of investments with a dollar-weighted average duration of normally no more than one half (0.5) of a year. Short Duration Municipal Fund seeks to reduce changes in the value of its shares by maintaining a portfolio of investments with a dollar-weighted average duration of normally one to ten years, Strategic Municipal Income Fund seeks to maintain a portfolio of investments with a certain dollar-weighted average effective duration, and each of the other Fixed Income Funds may from time to time seek to reduce changes in the value of its shares by maintaining a portfolio of investments with a particular dollar-weighted average duration, or may otherwise monitor a portfolio’s duration. Duration is an estimate of the sensitivity of a debt obligation to changes in interest rates, and is consequently a measure of interest rate risk. The duration of a given debt obligation represents an approximation of the expected percentage change in a debt obligation’s value in response to a change in interest rates. Duration is commonly expressed as a number of years, and the value of an obligation or a portfolio of obligations with a higher number—a longer duration—will be more volatile in response to changes in interest rates.

Computations of duration for a specific debt obligation or for a portfolio of debt obligations will vary depending upon various factors, including the assumptions employed in performing the computations. Because duration figures are estimates, the actual changes in market values of specific debt obligations or portfolios of obligations may be different from the estimated changes in valuations based upon durations computed for the obligations or portfolios of obligations.

Each of the Funds may purchase debt obligations which are of lower-quality at the time of purchase or which, due to issuer default or credit ratings downgrades, are determined subsequent to purchase to be of lower-quality. Under normal conditions, Ultra Short Income Fund, Core Plus Bond Fund, Short Duration Municipal Fund, Limited Term Municipal Fund, Intermediate Municipal Fund, Strategic Municipal Income Fund, Limited Term California Fund, Intermediate New Mexico Fund, and Intermediate New York Fund each may invest a significant portion (but with respect to the Ultra Short Income Fund less than twenty percent, with respect to Short Duration Municipal Fund, Limited Term Municipal Fund, Intermediate Municipal Fund, Limited Term California Fund, Intermediate New Mexico Fund, and Intermediate New York Fund up to twenty percent, with respect to Core Plus Bond Fund up to twenty five percent, and with respect to the Strategic Municipal Income Fund up to fifty percent) of its portfolio in such lower-quality debt obligations.

For these purposes, “lower-quality” debt obligations include debt obligations rated below Baa by Moody’s or BBB by S&P, and unrated securities judged by Thornburg to be of equivalent quality. Lower-quality debt obligations typically have poor protection with respect to the payment of interest and repayment of principal, and may be in default. These obligations are often considered to be speculative and involve greater risk of loss or price changes due to changes in the issuer’s capacity to pay. The market prices of lower-quality debt obligations may fluctuate more than those of higher-quality debt obligations and may decline significantly in periods of general economic difficulty, which may follow periods of rising interest rates.

The market for lower-quality debt obligations may be thinner and less active than that for higher-quality debt obligations, which can adversely affect the prices at which the former are sold. If a Fund experiences unexpected net redemptions, it could be forced to sell lower-quality debt obligations in its portfolio at disadvantageous prices without regard to those obligations’ investment merits, which could depress the Fund’s net asset value and reduce the Fund’s overall investment performance. If market quotations are not available, lower-quality debt obligations will be valued in accordance with procedures established by Thornburg, subject to the oversight of the Trustees, including the use of outside pricing services. Judgment plays a greater role in valuing lower-quality debt obligations than is the case for securities for which more external sources for quotations and last-sale information are available. Adverse publicity and changing investor perceptions may affect the ability of outside pricing services to value lower-quality debt obligations and a Fund’s ability to sell these securities. Since the risk of default is higher for lower-quality debt obligations, Thornburg’s research and credit analysis are an especially important part of managing securities of this type held by a Fund. In considering investments for a Fund, Thornburg will attempt to identify those issuers of high-yielding securities whose financial condition is adequate to meet future obligations, has improved, or is expected to improve in the future. Thornburg’s analysis focuses on relative values based on such factors as interest or dividend coverage, asset coverage, earnings prospects, and the experience and managerial strength of the issuer.

A Fund may choose, for example in the event of a default by the issuer of a debt obligation, at its expense or in conjunction with others, to pursue litigation or otherwise to exercise its rights as a security holder to seek to protect the interests of security holders if it determines this to be in the best interest of the Fund’s shareholders.

The Funds may also invest from time to time in unrated obligations, and Strategic Municipal Income Fund may invest a significant portion of its portfolio in municipal obligations that are unrated. Unrated obligations may be less liquid than comparable rated obligations and may be more difficult to value. Moreover, unrated obligations may be more difficult for Thornburg to evaluate and there is the risk that Thornburg may not accurately evaluate an investment’s actual credit quality. In particular, an unrated obligation that Thornburg believes is equivalent to an investment grade obligation could ultimately exhibit characteristics associated with lesser rated obligations.

Mortgage-Backed Securities, Mortgage Pass-Through Securities and Asset-Backed Securities

Mortgage-Backed Securities. Each of the Funds may invest in mortgage-backed securities, in debt obligations which are secured with collateral consisting of mortgage-backed securities (see “Structured Finance Arrangements - Collateralized Mortgage Obligations” below), and in other types of mortgage-related securities.

Mortgage-backed securities are interests in pools of mortgage loans, including mortgage loans made by savings and loan institutions, mortgage bankers, commercial banks and others. Pools of mortgage loans are assembled as securities for sale to investors by various governmental, government-related and private organizations. A decline in interest rates may lead to a faster rate of repayment of the underlying mortgages, which may expose a Fund to a lower rate of return upon reinvestment of the prepayments. Additionally, the potential for prepayments in a declining interest rate environment might tend to limit to some degree the increase in net asset value of a Fund because the value of some mortgage-backed securities held by a Fund may not appreciate as rapidly as the price of non-callable debt obligations. During periods of increasing interest rates, prepayments likely will be reduced, and the value of the mortgage-backed securities will decline.

Interests in pools of mortgage-backed securities differ from other forms of debt obligations. Whereas other forms of debt obligations normally provide for periodic payment of interest in fixed amounts with principal payments at maturity or specified call dates, mortgage-backed securities provide a monthly payment which consists of both interest and principal payments. In effect, these payments are a “pass-through” of the monthly payments made by the individual borrowers on their mortgage loans, net of any fees paid to the issuer or insurer of such securities. Additional payments are caused by repayments of principal resulting from the sale of the underlying property, or upon refinancing or foreclosure, net of fees or costs which may be incurred. Some mortgage-related securities (such as securities issued by the Government National Mortgage Association) are described as “modified pass-through.” These securities entitle the holder to receive all interest and principal payments owed on the mortgage pool, net of certain fees, on the scheduled payment dates regardless of whether or not the mortgagor actually makes the payment.

The principal governmental guarantor of mortgage-related securities is the Government National Mortgage Association (“Ginnie Mae”). Ginnie Mae is a wholly-owned United States Government corporation within the Department of Housing and Urban Development. Ginnie Mae is authorized to guarantee, with the full faith and credit of the United States government, the timely payment of principal and interest on securities issued by institutions approved by Ginnie Mae (such as savings and loan institutions, commercial banks and mortgage bankers) and backed by pools of mortgages insured or guaranteed by the Federal Housing Administration, the U.S. Department of Veteran Affairs or the Farmers Home Administration. These guarantees, however, do not apply to the market value or yield of mortgage-backed securities or to the value of Fund shares. Also, Ginnie Mae securities often are purchased at a premium over the maturity value of the underlying mortgages. This premium is not guaranteed and will be lost if prepayment occurs.

Government-related guarantors (i.e., not backed by the full faith and credit of the United States Government) include the Federal National Mortgage Association (“Fannie Mae”) and the Federal Home Loan Mortgage Corporation (“Freddie Mac”). Fannie Mae is a government-sponsored corporation subject to general regulation by the Secretary of Housing and Urban Development. Fannie Mae purchases conventional (i.e., not insured or guaranteed by any government agency) mortgages from a list of approved seller/servicers which include state and federally-chartered savings loan associations, mutual savings banks, commercial banks and credit unions and mortgage bankers. Pass-through securities issued by Fannie Mae are guaranteed as to timely payment of principal and interest by Fannie Mae but are not backed by the full faith and credit of the United States Government. Freddie Mac is a corporate instrumentality of the United States Government and was created by Congress in 1970 for the purpose of increasing the availability of mortgage credit for residential housing. Its stock is owned by the twelve Federal Home Loan Banks. Freddie Mac issues Participation Certificates (“PCs”), which represent interests in conventional mortgages from Freddie Mac’s national portfolio. Freddie Mac guarantees the timely payment of interest and ultimate collection of principal, but PCs are not backed by the full faith and credit of the United States Government.

In September 2008, the U.S. Government placed Fannie Mae and Freddie Mac into conservatorship overseen by the Federal Housing Finance Authority. That arrangement is intended to provide additional financial support to Fannie Mae and Freddie Mac. Since 2009, Fannie Mae and Freddie Mac have also each received significant capital support through the purchase of United States Treasury stock, and the United States Treasury has announced its expectation that it would continue providing such support in order to prevent either Fannie Mae or Freddie Mac from having negative net worth. Despite these measures, there can be no assurance that Fannie Mae and Freddie Mac will remain successful in meeting their financial commitments under the debt obligations that they issue or guarantee. There is also an ongoing debate among federal policy makers regarding whether Fannie Mae and Freddie Mac should be nationalized, privatized, restructured, or eliminated altogether.

Mortgage Pass-Through Securities. Ultra Short Income Fund, Limited Term Income Fund, Core Plus Bond Fund, Strategic Income Fund, each of the Equity Funds, and Summit Fund may also purchase pass-through pools of conventional mortgage loans that have been created by commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers. Such issuers may, in addition, be the originators and/or servicers of the underlying mortgage loans as well as the guarantors of the mortgage-related securities. Pools created by such non-governmental issuers generally offer a higher rate of interest than government and government-related pools because there are no direct or indirect government or agency guarantees of payments. Timely payment of interest and principal of these pools may be supported by various forms of insurance or guarantees, including individual loan, title, pool and hazard insurance and letters of credit. The insurance and guarantees are issued by governmental entities, private insurers and the mortgage poolers. Such insurance and guarantees and the creditworthiness of the issuers thereof will be considered in determining whether a mortgage-related security meets a Fund’s investment quality standards, if any. There can be no assurance that the private insurer or guarantors can meet their obligations under the insurance policies or guarantee arrangements. A Fund may buy mortgage-related securities without insurance or guarantees if, through an examination of the loan experience and practices of the originators/servicers and poolers, Thornburg determines that the securities meet the Fund’s quality standards. Although the market for such securities is becoming increasingly liquid, securities issued by certain private organizations may not be readily marketable.

Asset-Backed Securities. Ultra Short Income Fund, Limited Term Income Fund, Core Plus Bond Fund, Strategic Income Fund, each of the Equity Funds, and Summit Fund may invest in asset-backed securities.

The securitization techniques used to develop mortgage-backed securities (see “Mortgage-Backed Securities” and “Mortgage Pass-Through Securities” above) are also applied to a broad range of assets. Through the use of trusts and special purpose corporations, various types of assets, including automobile loans, computer leases and credit card receivables, are securitized in pass-through structures similar to the mortgage pass-through structures described below or in structures similar to the CMO pattern (see “Structured Finance Arrangements -- Collateralized Mortgage Obligations” below). In general, the collateral supporting these securities is of shorter maturity than mortgage loans and is less likely to experience substantial prepayments with interest rate fluctuations.

holders, and are guaranteed up to certain amounts and for a certain time period by a letter of credit issued by a financial institution unaffiliated with the trustee or originator of the trust. An investor’s return on CARS may be affected by early prepayment of principal on the underlying vehicle sales contracts. If the letter of credit is exhausted, the trust may be prevented from realizing the full amount due on a sales contract because of state law requirements and restrictions relating to foreclosure sales of vehicles and the obtaining of deficiency judgments following such sales or because of depreciation, damage or loss of a vehicle, the application of federal and state bankruptcy and insolvency laws, or other factors. As a result, certificate holders may experience delays in payments or losses if the letter of credit is exhausted.

Asset-backed securities may present certain risks that are not presented by mortgage-backed securities. Primarily, these securities may not have the benefit of any security interest in the related assets. Credit card receivables are generally unsecured and the debtors are entitled to the protection of bankruptcy laws and of a number of state and federal consumer credit laws, many of which give such debtors the right to set off certain amounts owed on the credit cards, thereby reducing the balance due. There is the possibility that recoveries on repossessed collateral may not, in some cases, be available to support payments on these securities.

Asset-backed securities are often backed by a pool of assets representing the obligations of a number of different parties. To lessen the effect of failures by obligors on underlying assets to make payments, the securities may contain elements of credit support which fall into two categories: (i) liquidity protection; and (ii) protection against losses resulting from ultimate default by an obligor on the underlying assets. Liquidity protection refers to the provision of advances, generally by the entity administering the pool assets, to ensure that the receipt of payment on the underlying pool occurs in a timely fashion. Protection against losses results from payment of the insurance obligations on at least a portion of the assets in the pool by the issuer or sponsor from third parties, through various means of structuring the transaction or through a combination of such approaches. Each of Ultra Short Income Fund and Limited Term Income Fund, as a possible purchaser of such securities, will not pay any additional or separate fees for credit support. The degree of credit support provided for each issue is generally based on historical information respecting the level of credit risk associated with the underlying assets. Delinquency or loss in excess of that anticipated or failure of the credit support could adversely affect the return on an investment in such a security.

Ultra Short Income Fund, Limited Term Income Fund, Core Plus Bond Fund, Strategic Income Fund, each of the Equity Funds, and Summit Fund may also invest in residual interests in asset-backed securities. In the case of asset-backed securities issued in a pass-through structure, the cash flow generated by the underlying assets is applied to make required payments on the securities and to pay related administrative expenses. The residual in an asset-backed security pass-through structure represents the interest in any excess cash flow remaining after making the foregoing payments. The amount of the residual will depend on, among other things, the characteristics of the underlying assets, the coupon rates on the securities, prevailing interest rates, the amount of administrative expenses and the actual prepayment experience on the underlying assets. Asset-backed security residuals not registered under the Securities Act of 1933 (the “1933 Act”) may be subject to certain restrictions on transferability. In addition, there may be no liquid market for such securities.

The availability of asset-backed securities may be affected by legislative or regulatory developments. It is possible that such developments may require a Fund holding these securities to dispose of the securities.

Thornburg expects that governmental, government-related or private entities may create mortgage-backed, mortgage pass-through and asset-backed securities in addition to those described above. If otherwise consistent with a Fund’s investment objectives, policies and quality standards, Thornburg may consider investing on behalf of a Fund in such new types of investments.

Each Fund may invest in municipal obligations. In particular, each Municipal Fund’s assets will normally consist of (1) municipal obligations or participation interests therein that are rated at the time of purchase within the four highest credit rating grades by Moody’s or S&P, (2) municipal obligations or participation interests therein that are not rated by a rating agency, but are issued by obligors that have other comparable debt obligations that are rated within the four highest credit rating grades by Moody’s or S&P, or in the case of obligors whose obligations are unrated, are deemed by Thornburg to be comparable with issuers having such debt ratings, and (3) a small amount of cash or equivalents.

Municipal obligations include debt and lease obligations issued by states, cities and local authorities to obtain funds for various public purposes, including the construction of a wide range of public facilities such as airports, bridges, highways, housing, hospitals, mass transportation, schools, streets and water and sewer works. Other public purposes for which municipal obligations may be issued include the refunding of outstanding obligations, the procurement of funds for general operating expenses and the procurement of funds to lend to other public institutions and facilities. In addition, certain types of industrial development bonds are issued by or on behalf of public authorities to obtain funds to provide privately-operated housing facilities, sports facilities, convention or trade show facilities, airport, mass transit, port or parking facilities, air or water pollution control facilities and certain local facilities for water supply, gas, electricity or sewage or solid waste disposal. Municipal obligations have also been issued to finance single-family mortgage loans and to finance student loans. Such obligations are included within the term “municipal obligations” for this discussion if the interest paid thereon is exempt from federal income tax.

Municipal obligations are generally classified as municipal bonds or municipal notes. A municipal bond typically has a maturity of more than one year and is issued by a state, city or local authority to meet longer-term capital needs. The two principal classifications of municipal bonds are “general obligation” and “revenue” bonds. General obligation bonds are secured by the issuer’s pledge of its faith, credit and taxing power for the payment of principal and interest. Revenue bonds are payable only from the revenues derived from a particular facility or class of facilities or, in some cases, from the proceeds of a specific revenue source. Industrial development bonds are in most cases revenue bonds and are generally not secured by the pledge of the credit or taxing power of the issuer of such bonds. There are, of course, variations in the security of municipal bonds, both within a particular classification and between classifications, depending on numerous factors. In contrast to municipal bonds, municipal notes typically have a maturity of one year or less and are issued by states, cities and local authorities to provide for short-term capital needs, often as an interim step in anticipation of the municipality receiving future revenue.

At times, a significant portion of a Municipal Fund’s assets may be invested in municipal obligations that are related in a manner that they may be affected negatively by specific economic, business, legal or political developments. For example, if a Fund has invested in revenue bonds issued by political subdivisions to finance healthcare facilities, reductions in medical expense reimbursements by private insurers or governmental agencies could have a negative impact on the revenues of those facilities and the ability of those

facilities to service the revenue bonds. Similarly, if a Fund has invested in municipal obligations originating in a specific state, then adverse fiscal or economic developments in the state could negatively affect both general obligation and revenue bonds issued by the state and its political subdivisions, agencies and instrumentalities. See also the discussions below entitled “Certain Factors Affecting Limited Term California Fund,” “Certain Factors Affecting Intermediate New Mexico Fund” and “Certain Factors Affecting Intermediate New York Fund.”

From time to time, proposals have been introduced before Congress for the purpose of restricting or eliminating the federal income tax exemption for interest on municipal securities. Similar proposals may be introduced in the future. These proposals, if enacted, may have the effect of reducing the availability of investments in municipal obligations and may adversely affect the value of a Fund’s portfolio. In addition, the Municipal Funds could be compelled to reevaluate their investment objectives and policies and submit possible changes in the structure of the Funds for the approval of their respective shareholders. Although the interest received from municipal securities generally is exempt from federal income tax, a Municipal Fund may invest a portion of its total assets in municipal securities subject to the federal alternative minimum tax (See “Additional Matters Respecting Taxes; Municipal Funds - Income Dividends” below for more information).

Auction Rate Securities. An auction rate security is a municipal obligation with a long-term nominal maturity for which the interest rate is reset at specific shorter frequencies (typically every seven to 35 days) through an auction process. The auction is a competitive bidding process used to determine interest rates on each auction date. In the auction, broker dealers submit bids to the auction agent on behalf of investors. The winning bid rate is the rate at which the auction clears, meaning the lowest possible interest rate at which the specific issue of municipal obligations can be sold at par. The clearing rate of interest established in the auction is paid on the entire issue of the municipal obligations for the upcoming period to the holders of those obligations. Investors who bid an interest rate above the clearing rate of interest receive no portion of the issue of municipal obligations, while those whose bids were at or below the clearing rate receive the clearing rate for the next period. Although the auction rate process is intended to permit the holders of a given issue of municipal obligations to sell their holdings at par in the auction at specified intervals, there is the risk that an auction will fail due to an insufficient demand for the obligations that are the subject of the auction, preventing the holders of the obligations from disposing of their holdings, potentially for an indeterminate period of time. In addition, auction rate securities may be subject to changes in interest rates, including decreased interest rates, thereby reducing the yields to holders of the obligations.

Fixed Rate Demand Obligations. A Fund may purchase fixed rate municipal demand obligations or instruments either in the public market or privately. Such instruments may provide for periodic adjustment of the interest rate paid to the holder. The “demand” feature permits the holder to demand payment of principal and interest prior to the instrument’s final stated maturity, either from the issuer or by drawing on a bank letter of credit, a guarantee or insurance issued with respect to the instrument. In some cases these demand instruments may be in the form of units, each of which consists of (i) a municipal obligation and (ii) a separate put option entitling the holder to sell to the issuer of such option the municipal obligation in the unit, or an equal aggregate principal amount of another municipal obligation of the same issuer, issue and maturity as the municipal obligation, at a fixed price on specified dates during the term of the put option. In those cases, each unit taken as a whole will be considered a municipal obligation, based upon an accompanying opinion of counsel. Each Municipal Fund except for Strategic Municipal Income Fund will invest in a fixed rate municipal demand instrument only if the instrument or the associated letter of credit, guarantee or insurance is rated within the three highest grades of a nationally recognized rating agency, or, if unrated, is deemed by Thornburg to be of comparable quality with issues having such debt ratings. The credit quality of such investments will be determined by Thornburg at the time of purchase, and will be reviewed by Thornburg from time to time thereafter. Strategic Municipal Income Fund may invest in fixed rate municipal demand instruments of any credit quality.

Floating Rate and Variable Rate Demand Obligations. Floating rate and variable rate demand notes, obligations or instruments are municipal obligations or participations therein, either publicly underwritten and traded or privately purchased, that provide for a periodic adjustment of the interest rate paid on the instrument and may permit the holder to demand payment of the unpaid principal amount and accrued interest upon not more than seven days’ notice either from the issuer or by drawing on a bank letter of credit, a guarantee or insurance issued with respect to such instrument. Such letters of credit, guarantees or insurance will be considered in determining whether a municipal obligation meets the Fund’s investment criteria. The issuer of a variable rate demand instrument may have the corresponding right to prepay the principal amount prior to maturity.

Mortgage-Backed Municipal Obligations. Some municipal obligations a Fund may purchase are backed by mortgage loans made by financial institutions or governmental agencies to finance single and multi-family housing projects or other real estate-related projects. Repayment of these municipal obligations may be secured by the revenues from a single housing project, or may be secured by a number of housing units. Interests in securities backed by a pool of mortgages on multiple housing units differ from other forms of debt obligation, which normally provide for periodic payment of interest in fixed amounts with principal payments at maturity or specified payment dates. Instead, these securities provide for a periodic (typically monthly) payment which consists of both interest and principal payments. For more information about the characteristics and risks of mortgage-backed securities, see “Mortgage-Backed Securities, Mortgage Pass-Through Securities and Asset-Backed Securities” above.

Municipal Leases. A Fund may at times invest in municipal obligations, including lease revenue bonds and certificates of participation, which provide the Fund with a proportionate interest in payments made by the governmental issuer on an underlying municipal lease. Although municipal lease obligations do not constitute general obligations of the governmental issuer for which the issuer’s taxing power is pledged, these lease obligations are typically backed by the issuer’s covenant to budget for, appropriate and make the payments due on the underlying lease. However, certain municipal lease obligations may include “non-appropriation” clauses, which provide that the governmental issuer has no obligation to make lease payments unless money is appropriated each year for that purpose. While the lease obligation might be secured by the leased property, it might be difficult for a Fund to dispose of the leased property in case of a default by the governmental lessee. In addition, some municipal lease obligations may be less liquid than other debt obligations, making it difficult for a Fund to sell the obligation at an acceptable price. In seeking to reduce the special risks associated with investment by a Fund in municipal lease obligations, Thornburg will consider: (i) whether the underlying lease can be canceled; (ii) whether the nature of the leased equipment or property is such that its ownership or use is deemed essential to a governmental function of the governmental lessee (e.g., the potential for an “event of nonappropriation”); (iii) in cases where the obligation gives a Fund a secured interest in the underlying equipment, whether that equipment has elements of portability or use that enhance its marketability in the event of a default by the governmental lessee; (iv) whether the governmental issuer’s general credit is adequate; and (v) such other factors concerning credit quality or the Fund’s legal recourse in the event of a default by the governmental issuer as Thornburg may deem relevant. Thornburg will also evaluate the liquidity of each municipal lease obligation upon its acquisition and periodically while it is held based upon various factors, including: (a) the frequency of trades and quotes for the obligation; (b) the number of dealers who will buy or sell the obligation and the potential buyers for the obligation; (c) the willingness of dealers to make

a market for the obligation; (d) the nature and timing of marketplace trades; and (e) such other factors concerning the trading market as Thornburg may deem relevant.

Tender Option Bonds. Each of the Funds may invest in tender option bonds. Tender option bonds are created when the owner or owners of one or more fixed rate municipal obligations sell or transfer those obligations to a trust that is sponsored by a broker-dealer or other third party. The trust then issues two new securities, each of which represents a beneficial interest in the trust. One of these securities is a short-term, floating-rate security, sometimes referred to as a “senior certificate” or a “floater.” The interest rate on the senior certificate is initially set at a level that is lower than the interest rate on the underlying municipal obligation(s), and resets periodically based on the movement of a short-term benchmark interest rate. The senior certificates also have a demand feature which permits the security holder to put the security back to the trust after a specified notice period. In that event the security holder is entitled to receive the principal amount of the senior certificate plus accrued interest. Those amounts are paid by either the sponsor of the trust or by a third party that acts as a liquidity provider for the trust. The other security issued by the trust is a long-term, floating-rate security, sometimes referred to as a “residual interest” or an “inverse floater.” The residual interests pay an interest rate equal to the interest that is paid on the underlying municipal obligation(s) less the interest that was paid to the holders of the senior certificates and less any expenses of the trust. Unlike the senior certificates, the residual interest securities do not have a put feature. Upon maturity of the underlying municipal obligation(s) or another event which causes the termination or liquidation of the trust, holders of the senior certificates are generally entitled to receive the principal amount of their security plus a portion of any gains in the market value of the underlying municipal obligations, while holders of the residual interest are generally entitled to receive whatever amounts remain in trust after payment to the senior certificate holders and payment of trust expenses.

The senior certificates are sold to third parties, which may include the Funds, in a private placement transaction. Because the senior certificates have first priority to the cash flows from the underlying municipal obligation(s), and because the holders of senior certificates have a right to put those securities back to the trustee or to a third party liquidity facility, investments in senior securities are generally perceived as involving less interest rate, credit, and market risk than investments in the residual interests. Investors in senior certificates are, however, exposed to the risk that the trust sponsor or third party liquidity facility fails to meet its contractual obligation to buy back the security when the investor exercises its put option.

The residual interests are issued to the person(s) that transferred the municipal obligation(s) to the trust. The residual interest holders also receive the proceeds from the sale of the senior certificates, less certain transaction costs and trustee fees. Risks associated with an investment in residual interests include the risks associated with an investment in the underlying municipal obligations, and the risk that increases in short-term interest rates will increase interest payments to the senior certificate holders and therefore reduce interest payments to the residual interest holders. Investments in residual interests also typically involve leverage, which may magnify an investor’s losses.

Certain Factors Affecting Limited Term California Fund. Limited Term California Fund invests primarily in municipal obligations originating in California. For this reason an investment in Limited Term California Fund may be riskier than an investment in Limited Term Municipal Fund, which buys debt obligations from throughout the U.S. Prospective investors should consider the risks inherent in the investment concentration of Limited Term California Fund before investing. The information shown below is derived from sources generally available to investors as of the date of this Statement of Additional Information. The information has not been independently verified by the Funds. The information does not represent a complete analysis of every material fact affecting the debt obligations of the state or its municipalities, nor is it intended to indicate future or continuing economic trends in California.

California has a population of approximately 39 million, the largest of the 50 states. Its economy is the largest of the 50 states and among the largest in the world when compared with other countries. In terms of jobs, the five largest sectors of California’s economy are trade, transportation and utilities; government; professional and business services; education and health services; and leisure and hospitality. In terms of output, the five largest sectors of California’s economy are financial services; trade, transportation and utilities; education and health services; government; and manufacturing. The state is also a major agricultural producer, with the highest agricultural output of any U.S. state.

According to the U.S. Department of Labor’s Bureau of Labor Statistics, California’s unemployment rate was 4.8% in October 2023, exceeding the national average of 3.8% for that month. To help meet its state debt obligations, California relies on state tax collections which ranked 2nd highest in the nation in 2022 on a per capita basis, according to the most recent data available from the Federation of Tax Administrators, an organization of state tax officials. State tax collections totaled approximately $7,195 per capita in 2022. Approximately 52.1% of the state’s tax collections in 2022 came from state individual income taxes, approximately 25.7% of tax collections in 2022 came from sales/excise taxes, and the balance of 2022 tax collections came from corporate income taxes, property taxes, and other tax sources.

Certain Factors Affecting Intermediate New Mexico Fund. Intermediate New Mexico Fund invests primarily in municipal obligations originating in New Mexico. For this reason an investment in Intermediate New Mexico Fund may be riskier than an investment in Intermediate Municipal Fund, which buys debt obligations from throughout the United States. Prospective investors should consider the risks inherent in the investment concentration of Intermediate New Mexico Fund before investing. The following disclosure provides a brief summary of certain economic information about the state of New Mexico. The information shown below is derived from sources generally available to investors as of the date of this Statement of Additional Information. The information has not been independently verified by the Funds. The information does not represent a complete analysis of every material fact affecting the debt obligations of the state or its municipalities, nor is it intended to indicate future or continuing economic trends in New Mexico.

New Mexico has a population of approximately 2.1 million, the 37th most populous state in the U.S. Oil and gas production, tourism and government spending are important drivers of the New Mexico economy. Major federally funded scientific research facilities at Los Alamos, Albuquerque, and White Sands are also important parts of the state economy and have to some extent helped reduce the state’s exposure to local and national economic cycles.

According to the U.S. Department of Labor’s Bureau of Labor Statistics, New Mexico’s unemployment rate was 3.8% in October 2023, equal to the national average of 3.8% for that month. To help meet its state debt obligations, New Mexico relies on state tax collections which ranked 26th in the nation in 2022 on a per capita basis, according to the most recent data available from the Federation of Tax Administrators, an organization of state tax officials. State tax collections totaled approximately $4,070 per capita in 2022. Approximately 48.7% of the state’s tax collections in 2022 came from sales/excise taxes, approximately 15.1% of tax collections in 2022 came from state individual income taxes, and the balance of 2022 tax collections came from corporate income taxes, property taxes, and other tax sources.

Certain Factors Affecting Intermediate New York Fund. Intermediate New York Fund invests primarily in municipal obligations originating in New York. For this reason, an investment in Intermediate New York Fund may be riskier than an investment in Intermediate Municipal Fund, which buys debt obligations from throughout the U.S. Prospective investors should consider the risks inherent in the investment concentration of Intermediate New York Fund before investing. The following disclosure provides a brief summary of certain economic information about the state of New York. The information shown below is derived from sources generally available to investors as of the date of this Statement of Additional Information. The information has not been independently verified by the Funds. The information does not represent a complete analysis of every material fact affecting the debt obligations of the state or its municipalities, nor is it intended to indicate future or continuing economic trends in New York.

New York has a population of approximately 19.6 million, fourth largest in the U.S. New York City dominates the economy of the state. It is a leading center of banking, finance, communications, insurance, and real estate in the U.S. Tourism is a significant source of economic activity. The state is also a major agricultural producer. Its industrial outputs include printing and publishing, scientific instruments, electronic equipment, machinery, and chemicals.

According to the U.S. Department of Labor’s Bureau of Labor Statistics, New York’s unemployment rate was 4.2% in October 2023, exceeding the national average of 3.8% for that month. To help meet its state debt obligations, New York relies on state tax collections which ranked 10th highest in the nation in 2022 on a per capita basis, according to the most recent data available from the Federation of Tax Administrators, an organization of state tax officials. State tax collections totaled approximately $5,996 per capita in 2022, approximately 59.5% of the state’s tax collections in 2022 came from individual income taxes, approximately 36.5% of tax collections in 2022 came from sales/excise taxes, and the balance of 2022 tax collections came from corporate income taxes and other tax sources.

Collateralized Mortgage Obligations (“CMOs”). Limited Term U.S. Government Fund, Ultra Short Income Fund, Limited Term Income Fund, Core Plus Bond Fund, Strategic Income Fund, each of the Equity Funds, and Summit Fund may invest in CMOs.

A CMO is a hybrid between a mortgage-backed bond and a mortgage pass-through security (see discussion of those instruments under “Mortgage-Backed Securities, Mortgage Pass-Through Securities and Asset-Backed Securities” above). Similar to a bond, interest and prepaid principal are paid, in most cases, semiannually. CMOs may be collateralized by whole mortgage loans but are more typically collateralized by portfolios of mortgage pass-through securities guaranteed by Ginnie Mae, Freddie Mac, or Fannie Mae, and their income streams.

CMOs are structured into multiple classes, each bearing a different stated maturity. Actual maturity and average life will depend upon the prepayment experience of the collateral. CMOs provide for a modified form of call protection through a de facto breakdown of the underlying pool of mortgages according to how quickly the loans are repaid. Monthly payment of principal received from the pool of underlying mortgages, including prepayments, is first returned to investors holding the shortest maturity class. Investors holding the longer maturity classes receive principal only after the first class has been retired. An investor is partially guarded against unanticipated early return of principal because of the sequential payments.

In a typical CMO transaction, a corporation issues multiple series, (e.g., A, B, C, Z) of CMO bonds. Proceeds of the offering are used to purchase mortgage pass-through certificates (the “collateral”). The collateral is pledged to a third party trustee as security for the CMO bonds. Principal and interest payments from the collateral are used to pay principal on the CMO bonds in the order A, B, C, Z. The Series A, B, and C bonds all bear current interest. Interest on the Series Z bond is accrued and added to principal and a like amount is paid as principal on the Series A, B, or C bond currently being paid off. Once the Series A, B, and C bonds are paid in full, interest and principal on the Series Z Bond begins to be paid currently. With some CMOs, the issuer serves as a conduit to allow loan originators (primarily builders or savings and loan associations) to borrow against their loan portfolios.

The market for some CMOs may be less liquid than other debt obligations, making it difficult for a Fund to value its investment in the CMO or sell the CMO at an acceptable price.

Limited Term U.S. Government Fund, Ultra Short Income Fund, Limited Term Income Fund, Strategic Income Fund, each of the Equity Funds, and Summit Fund may also invest in CMOs issued by Freddie Mac. Like other CMOs, Freddie Mac CMOs are issued in multiple classes having different maturity dates. Freddie Mac CMOs are secured by the pledge of a pool of conventional mortgage loans purchased by Freddie Mac. Payments of principal and interest on the CMOs are typically made semiannually, as opposed to monthly. The amount of principal payable on each semiannual payment date is determined in accordance with Freddie Mac’s mandatory sinking fund schedule, which, in turn, is equal to approximately 100% of the Federal Housing Administration prepayment experience applied to the mortgage collateral pool. All sinking fund payments in the CMOs are allocated to the retirement of the individual classes of bonds in the order of their stated maturities. Payment of principal on the mortgage loans in the collateral pool in excess of the amount of Freddie Mac’s minimum sinking fund obligation for any payment date are paid to the holders of the CMOs as additional sinking fund payments. Because of the “pass-through” nature of all principal payments received on the collateral pool in excess of Freddie Mac’s minimum sinking fund requirement, the rate at which principal of the CMOs is actually repaid is likely to be such that each class of bonds will be retired in advance of its scheduled date. If collection of principal (including prepayments) on the mortgage loans during any semiannual payment period is not sufficient to meet Freddie Mac’s minimum sinking fund obligation on the next sinking fund payment date, Freddie Mac agrees to make up the deficiency from its general funds. Criteria for the mortgage loans in the pool backing the CMOs are identical to those of Freddie Mac PCs. Freddie Mac has the right to substitute collateral in the event of delinquencies or defaults.

Other Structured Finance Arrangements. Each of the Equity Funds, Limited Term Income Fund, Ultra Short Income Fund, Core Plus Bond Fund, and Strategic Income Fund may also invest in other types of structured finance arrangements besides CMOs.

Other types of structured finance arrangements that are currently available for investment include collateralized bond obligations (“CBOs”), collateralized loan obligations (“CLOs”) and similarly structured securities. A CBO is a trust or other special purpose entity (“SPE”) which is typically backed by a diversified pool of fixed income securities (which may include high risk, below investment grade securities). A CLO is a trust or other SPE that is typically collateralized by a pool of loans, which may include, among others, domestic and non-U.S. senior secured loans, senior unstructured loans, and subordinate corporate loans, including loans rated

below investment grade or equivalent unrated loans. CMOs, CBOs, CLOs and other similarly structured securities are sometimes referred to generally as collateralized debt obligations (“CDOs”).

The cashflows from a CDO’s trust or SPE are split into two or more portions, called tranches, varying in risk and yield. The riskiest portion is the “equity” tranche, which bears the first loss from defaults from the bonds or loans in the trust or SPE and serves to protect the other, more senior tranches from defaults (though such protection is not complete). Since it is partially protected from defaults, a senior tranche from a CBO or CLO typically has higher ratings and lower yields than its underlying securities, and may be rated investment grade. Despite the protection from the equity tranche, CBO or CLO tranches can experience substantial losses due to actual defaults, increased sensitivity to defaults due to collateral default and the disappearance of protecting tranches, market anticipation of defaults, and/or investor aversion to CBO or CLO securities as a class. Interest on certain tranches of a CDO may be paid in kind (i.e., in the form of obligations of the same type, rather than cash), which involves continued exposure to default risk with respect to such payments.

Although certain CDOs may receive credit enhancement in the form of a senior-subordinate structure, over-collateralization or bond insurance, such enhancement may not always be present and may fail to protect the Fund against the risk of loss on default of the collateral. Certain CDOs may use derivative contracts, such as credit default swaps, to create “synthetic” exposure to assets rather than holding such assets directly, which entails the risk of derivative instruments described elsewhere in this Statement of Additional Information. See, e.g., “Investing in Derivative Instruments - Swap Agreements, Caps, Floors and Collars” below. CDOs may charge management fees and administrative expenses, which are in addition to those of the Fund. A Fund will not invest in CDOs that are managed by Thornburg or its affiliates.

The risks of investment in a CDO depend largely on the type of collateral securities and the class of the CDO in which a Fund invests. Normally, CBOs, CLOs and other CDOs are privately offered and sold, and thus, are not registered under the securities laws. As a result, investments in CDOs may be characterized by a Fund as illiquid investments. However, an active dealer market may exist for CDOs, which may allow a CDO to qualify for resale to qualified institutional buyers pursuant to Rule 144A under the 1933 Act. In addition to the normal risks associated with fixed income securities described elsewhere in this Statement of Additional Information and the Prospectus (e.g., interest rate risk and credit risk), CDOs carry additional risks including, but not limited to: (i) the possibility that distributions from collateral securities will not be adequate to make interest or other payments; (ii) the quality of the collateral may decline in value or default; (iii) the Fund may invest in tranches of CDOs that are subordinate to other tranches; (iv) the complex structure of the security may not be fully understood at the time of investment and may produce disputes with the issuer or unexpected investment results; and (v) the CDO’s manager may perform poorly.

Each of the Funds may invest in obligations of the U.S. Government. In the case of a Municipal Fund, its investment in U.S. Government Obligations is permitted as part of the Fund’s temporary investments in taxable securities (see “Other Investments and Investment Techniques - Temporary Investments” below).

U.S. Government Obligations include bills, certificates of indebtedness, notes and bonds issued or guaranteed as to principal or interest by the United States or by agencies or authorities controlled or supervised by, and acting as instrumentalities of, the U.S. government and established under the authority granted by Congress, including, but not limited to, Ginnie Mae, the Tennessee Valley Authority, the Bank for Cooperatives, the Farmers Home Administration, Federal Home Loan Banks, Federal Intermediate Credit Banks, Federal Land Banks, Farm Credit Banks and Fannie Mae. Some obligations of U.S. government agencies, authorities and other instrumentalities are supported by the full faith and credit of the U.S. Treasury; others by the right of the issuer to borrow from the Treasury; others only by the credit of the issuing agency, authority or other instrumentality. In the case of securities not backed by the full faith and credit of the United States, the investor must look principally to the agency issuing or guaranteeing the obligation for ultimate repayment, and may not be able to assert a claim against the United States itself in the event the agency or instrumentality does not meet its commitments. All U.S. Government Obligations are subject to the same risks affecting other debt obligations. Even if a U.S. Government Obligation is backed by the full faith and credit of the U.S. Treasury, it is possible that the U.S. government may be unable or unwilling to repay principal and interest when due, and may require that the terms for payment be renegotiated.

One specific type of U.S. Government Obligation is a Treasury Inflation Protected Security (“TIPS”). TIPS are debt obligations issued by the U.S. Treasury which are intended to protect investors from the negative effects of inflation. The principal value of the TIPS is periodically adjusted according to the rate of inflation, as measured by changes in the Consumer Price Index. Interest on TIPS is paid semi-annually as a fixed percentage of the inflation-adjusted principal amount. Typically, the interest rate on TIPS is lower than the interest rate paid on other U.S. Government Obligations of the same maturity.

Each of the Funds may purchase zero coupon bonds, including stripped securities.

Zero coupon bonds are corporate or government-issued debt obligations which do not require the periodic payment of interest and are issued at a significant discount from face value. The discount approximates the total amount of interest the bonds will accrue and compound over the period until maturity at a rate of interest reflecting the market rate of the obligation at the time of issuance.

A “stripped” security is a zero coupon bond created by separating the principal and interest cash flows from another debt obligation, typically a U.S. Treasury security. The principal component is often referred to as a “principal only” or “P/O” security, while the interest component is often referred to as an “income only” or “I/O” security.

Because zero coupon bonds pay no interest and compound semi-annually at the rate fixed at the time of their issuance, their market value is generally more volatile than the market value of comparable, interest-paying bonds, particularly during periods of changing interest rates. A Fund is required to accrue income from zero coupon bonds on a current basis even though it does not receive the income currently in cash, and a Fund is required to distribute that income for each taxable year. To generate the cash necessary to satisfy such distributions, a Fund invested in zero coupon bonds may have to sell portfolio securities that it otherwise might have continued to hold or use cash flows from other sources, including the sale of Fund shares.

Equity securities represent an ownership interest in the entity issuing the security. Common stocks, the most familiar type of equity security, represent an ownership interest in a corporation. The values of equity securities fluctuate significantly in response to changes in market conditions, political and economic news, changes in company earnings and dividends, changes in the prospects for company businesses, industry and technological developments, changes in interest rates, and developments affecting specific companies. When equity securities held by a Fund decline in value, the value of the Fund’s shares declines. These declines may be significant and there is no assurance that declines in value can be recaptured by future gains in value. When equity securities held in short position by a Fund increase in value, the Fund may experience a loss, as described in “Short Sales,” below.

The following discussion contains additional detail about equity securities, including some of the specific types of equity securities in which a Fund may invest and certain risks associated with those investments. You should read the Prospectus for more information about the characteristics and risks of equity securities. You should also read “Investing in Foreign Debt Obligations and Foreign Equity Securities” below for information about some of the characteristics and risks of foreign equity securities.

Each of the Equity Funds, Summit Fund, Ultra Short Income Fund, Strategic Income Fund, and Strategic Municipal Income Fund may invest in the shares of closed end funds, including closed end funds which have elected to be treated as business development companies under the Investment Company Act of 1940 (the “1940 Act”). Strategic Municipal Income Fund’s investment in the shares of closed end funds is limited to those closed end funds that invest in municipal obligations and distribute income that the Fund is permitted to designate as exempt interest dividends.

Closed end funds are investment companies that invest in various securities and other financial assets, and which issue shares that trade on exchanges in a manner similar to the shares of exchange traded funds (see “Exchange Traded Funds” below). The shares of a closed end fund change in value as the values of its component securities and other investments fluctuate with market changes. In contrast to exchange traded funds, however, the trading values of a closed end fund’s shares often diverge to a greater extent from the net asset value of the fund’s underlying portfolio investments. A closed end fund incurs its own operating expenses, so that if a Fund invests in a closed end fund, shareholders of the Fund bear the closed end fund’s expenses in addition to the expenses of the Fund.

Each of the Equity Funds, Summit Fund, Limited Term Income, Ultra Short Income Fund, Core Plus Bond Fund, and Strategic Income Fund may invest in convertible debt obligations, and each of the Equity Funds, Summit Fund, and Strategic Income Fund may also invest in convertible preferred equity securities.

Convertible debt obligations may be converted or exchanged within a specified period of time and under certain conditions into a certain amount of common stock of the same or a different issuer. As with non-convertible debt obligations, the market value of a convertible debt obligation may vary with changes in prevailing interest rates and changing evaluations of the ability of the issuer to meet principal and interest payments. The market value of a convertible debt obligation may also vary in accordance with the market value of the underlying stock. As a result, convertible debt obligations held by a Fund will tend to perform more like equity securities when the underlying stock price is high (because it is assumed that a Fund will convert the obligation), and more like non-convertible debt obligations when the underlying stock price is low (because it is assumed that a Fund will not convert the obligation). Because its market value can be influenced by several factors, a convertible debt obligation will not be as sensitive to interest rate changes as a similar non-convertible debt obligation, and generally will have less potential for gain or loss than the underlying stock.

As with convertible debt, a convertible preferred equity security may be converted or exchanged within a specified period of time and under certain conditions into a certain amount of common stock. The market value of the convertible preferred equity security typically varies in accordance with the market value of the underlying common stock and, accordingly, is subject to the same risks affecting the underlying common stock.

Each of the Equity Funds, Summit Fund, Limited Term Income Fund, Ultra Short Income Fund, Core Plus Bond Fund, Strategic Income Fund, and Strategic Municipal Income Fund and may invest in the shares of exchange traded funds (“ETFs”). Strategic Municipal Income Fund’s investment in the shares of ETFs is limited to those ETFs that invest in municipal obligations and distribute income that the Fund is permitted to designate as exempt interest dividends.

ETFs are investment companies that invest in various securities and financial assets. ETFs are created either to provide investment results corresponding to a securities index, or are actively managed in a manner corresponding more closely to a traditional mutual fund. ETFs are typically available to investors as units of beneficial interest in a trust, and are purchased and sold on an exchange in the same way as common stocks. The values of ETF shares increase and decline as the values of the ETF’s component securities and other investments fluctuate with the market changes, and usually trade in a relatively narrow range relative to the net asset value of its underlying portfolio investments because the structure of an ETF permits certain major market participants to redeem shares of the ETF for a “basket” of the ETF’s underlying investments. Shares in an ETF held by a Fund are consequently subject to the same general market risks that affect the underlying investments by the ETF, except that a Fund’s investments in an ETF may not exactly match the performance of any specific index (and may not perform as well as any specific index) because of differences between the ETF’s investments and the index or other factors. In addition, each ETF incurs its own operating expenses, so that if a Fund invests in an ETF, shareholders of the Fund bear the ETF’s expenses in addition to the expenses of the Fund.

From time to time a Fund may take short positions in leveraged ETFs. Leveraged ETFs are ETFs that use derivatives instruments or other investment techniques to try to generate returns that exceed the returns of their underlying portfolio investments. The use of leverage by ETFs tends to exaggerate the effect of any increase or decrease in the value of the ETF’s underlying investments and may, therefore, cause the value of the ETF’s shares to be more volatile than if the ETF did not use leverage.

Each of the Equity Funds, Summit Fund and Strategic Income Fund may invest in common stock or other equity securities offered through initial public offerings (“IPOs”).

An IPO is an issuer’s first offering of equity securities to the public. The issuer of IPO securities may have a limited operating history, and limited information about the issuer may be available to potential purchasers. Accordingly, the market for IPO securities may be more volatile and involve greater risk of loss than investments in the equity securities of more established companies. At times a Fund may sell its investment in IPO securities shortly after the Fund purchased those securities, which may result in increased transaction costs for the Fund. There can be no assurance that a Fund will have access to profitable IPOs and, as the Fund’s assets grow, any positive impact of IPO investments on the Fund’s performance likely will decline.

Smaller, less seasoned companies are generally subject to greater price fluctuations, limited market liquidity, higher transaction costs and generally higher investment risks. Smaller companies may have limited product lines, markets or financial resources, may have more limited management expertise and resources, and have more limited financing and capital. There may be less available information respecting these companies.

Each of the Equity Funds, Summit Fund and Strategic Income Fund may invest in interests issued by limited partnerships and master limited partnerships (“MLPs”). MLPs are business enterprises in which ownership interests are publicly traded, and which typically own interests in properties or businesses related to the oil and gas industries, although they may own other types of investments. Ownership interests in limited partnerships other than MLPs may not be publicly traded, which may decrease the liquidity of those investments. Investments in MLPs and other limited partnerships are subject to the risks associated with equity investments generally and to the risks associated with the specific industry or industries in which the partnership operates. Investments in MLPs and other limited partnerships are also subject to certain additional risks when compared to investments in corporations, including certain tax risks, a more limited ability for investors to elect or remove the issuer’s management, and more limited voting rights for investors.

Each of the Equity Funds, Summit Fund, Limited Term Income Fund, and Strategic Income Fund may invest in preferred stock.

Preferred stock is a class of stock that generally pays dividends at a specified rate and has preference over common stock in the payment of dividends and liquidation. Preferred stock generally does not carry voting rights. Preferred stock dividends are generally fixed in advance, but the issuing company may not be required to pay a dividend if, for example, it lacks the financial ability to do so. Dividends on preferred stock may be cumulative, meaning that, in the event the issuer fails to make one or more dividend payments on the preferred stock, no dividends may be paid on the issuer’s common stock until all unpaid preferred stock dividends have been paid. Preferred stock also may be subject to optional or mandatory redemption provisions.

Each of the Equity Funds, Summit Fund and Strategic Income Fund may invest in real estate investment trusts (“REITS”).

REITs are pooled investment vehicles that invest in real estate or real estate-related companies. Types of REITs in which a Fund may invest include equity REITs, which own real estate directly, mortgage REITs, which make construction, development, or long-term mortgage loans, and hybrid REITs, which share characteristics of equity REITs and mortgage REITs. A Fund may also invest in other real estate-related instruments, such as commercial and residential mortgage-backed securities and real estate financings.

Investments in REITs and other real-estate related instruments are subject to risks affecting real estate investments generally, including overbuilding, property obsolescence, casualty to real estate, and changes in real estate values, property taxes and interest rates. In addition, the value of a Fund’s investments in REITs may be affected by the quality and skill of the REIT’s manager, the internal expenses of the REIT, and, with regard to REITs issued in the United States, the risk that the REIT will fail to qualify for tax-free pass-through of income under the Internal Revenue Code of 1986 and/or maintain exemption from registration under the 1940 Act.

Each of the Equity Funds, Summit Fund and Strategic Income Fund may enter into short sales with respect to an investment that Thornburg believes to be overvalued or to hedge against the Fund’s long exposures. A Fund may engage in short selling with respect to any of the securities in which the Fund is permitted to invest, including domestic and foreign equity securities and debt obligations. Summit Fund may engage in short selling as a principal investment strategy.

In a short sale, the Fund borrows a security from a lender and then sells that borrowed security to another party. In order to complete the short sale, the Fund must return the borrowed security to the lender, which the Fund normally does by purchasing that security on the open market and delivering it to the lender. The Fund will realize a gain if the price of the security declines between the date the Fund borrowed the security and the date the Fund purchased the security to replace the borrowed security. The Fund will incur a loss if the price of the security increases between those dates. The Fund is required to pay to the lender amounts equal to any dividend or interest which accrues on the borrowed security during the period of the loan. The Fund may also be required to pay a premium, fee, or other amount to the lender in exchange for borrowing the security.

have to purchase the securities on the open market at a time when the securities’ prices are unfavorable. To the extent the Fund is required to deliver collateral to the lender in response to declines in the value of the Fund’s short positions, the Fund may have to sell other securities in its portfolio to meet those collateral requirements. Such sales may not be at favorable prices, or may impede the pursuit of the Fund’s investment strategy.

When the Fund sells securities short, it may use the proceeds from the sales to purchase long positions in additional securities that it believes will outperform the market or its peers. This strategy may effectively result in the Fund having a leveraged investment portfolio. The use of leverage tends to exaggerate the effect of any increase or decrease in the value of the Fund’s underlying investments, and may, therefore, cause the Fund’s share price to be more volatile.

The Summit Fund may also seek to achieve short exposure to an investment through the use of derivative instruments, which may involve risks different or greater than the risks affecting the investment that the Fund seeks to achieve short exposure to. See “Investing in Derivatives,” below.

Subject to certain limitations, as described in “Investment Limitations” below, each of the Equity Funds, Summit Fund, Limited Term Income Fund and Strategic Income Fund may invest in warrants and similar rights. A warrant represents an option to purchase a stated number of shares of common stock of an issuer at a specified price during a specified period of time. The prices of warrants will not always correlate with the prices of the underlying shares of stock. In addition to the risks relating to the underlying stock, the purchase of warrants involves the risk that the effective price paid for the warrant, when added to the subscription price of the underlying stock, will exceed the market price of the underlying stock. Rights represent a preemptive right to purchase additional shares of an issuer’s common stock at the time of a new offering of those shares, thereby permitting the rights holder to retain the same ownership percentage after the new offering.

Each of the Equity Funds, Summit Fund, Limited Term Income Fund and Strategic Income Fund may make investments in foreign debt obligations or foreign equity securities, and Ultra Short Income Fund and Core Plus Bond Fund may make investments in foreign debt obligations. Global Opportunities Fund, International Equity Fund, Better World International Fund, International Growth Fund, and Developing World Fund invest primarily in foreign securities, and Summit Fund invest in a portfolio of both domestic and foreign securities, and at times the portfolios of other Funds may contain a significant percentage of foreign securities.

A Fund’s investment in a foreign debt obligation or foreign equity security typically involves all of the risks inherent in the same type of debt obligation or equity security issued by a domestic issuer. In addition, foreign investments can involve significant risks in addition to the risks inherent in U.S. investments. The following discussion contains additional detail about the types of foreign investments which a Fund may make and certain risks associated with those investments. You should read the Prospectus for more information about these investments and their risks.

Foreign investments can involve significant risks in addition to the risks inherent in U.S. investments. The value of securities denominated in or indexed to foreign currencies, and of dividends and interest from such securities, can change significantly when foreign currencies strengthen or weaken relative to the U.S. dollar. Foreign securities markets generally have less trading volume and less liquidity than U.S. markets, and prices on some foreign markets can be highly volatile. Many foreign countries lack uniform accounting and disclosure standards comparable to those applicable to U.S. companies, and it may be more difficult to obtain reliable information regarding an issuer’s financial condition and operations. Some foreign countries impose conditions and restrictions on foreigners’ ownership of interests in local issuers, including restricting ownership to certain classes of investment in an issuer, which may reduce potential investment returns and impair disposition of those investments. In addition, the costs of foreign investing, including withholding taxes, brokerage commissions, and custodial costs, are generally higher than for U.S. investments.

Foreign markets may offer less protection to investors than U.S. markets. Foreign issuers, brokers, and securities markets may be subject to less government supervision. Foreign securities trading practices, including those involving the release of assets in advance of payment, may involve increased risks in the event of a failed trade or the insolvency of a broker-dealer, and may involve substantial delays. It may also be difficult to enforce legal rights in foreign countries, because of inconsistent legal interpretations or less defined legal and regulatory provisions, or because of corruption or influence on local courts.

Investing abroad also involves different political and economic risks. Foreign investments may be affected by actions of foreign governments adverse to the interests of U.S. investors, including the possibility of expropriation or nationalization of assets, confiscatory taxation, restrictions on U.S. investment or on the ability to repatriate assets or convert currency into U.S. dollars, or other government intervention. There may be a greater possibility of default by foreign governments or foreign government-sponsored enterprises, and securities issued or guaranteed by foreign governments, their agencies, instrumentalities, or political subdivisions, may or may not be supported by the full faith and credit and taxing power of the foreign government. Investments in foreign countries also involve a risk of local political, economic, or social instability, military action or unrest, or adverse diplomatic developments. There is no assurance that Thornburg will be able to anticipate these potential events or counter their effects.

American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”) and Global Depositary Receipts (“GDRs”) are certificates evidencing ownership of shares of a foreign-based issuer. These certificates are issued by a bank or similar financial institution and generally trade on an established securities market in the U.S. or elsewhere. An investment in ADRs, EDRs or GDRs is an alternative to the purchase of the underlying securities in their national markets and currencies. However, ADRs, EDRs and GDRs remain subject to many of the risks associated with investing directly in foreign securities, including the political and economic risks associated with the underlying issuer’s country. Additionally, the bank or other financial institution which issues the depositary receipt may charge the security holder fees for various services, such as forwarding dividend and interest payments. The Fund’s investments in depositary receipts evidencing ownership in shares of a developing country issuer will be deemed to be an investment in that developing country issuer for purposes of the Fund’s investment policies and restrictions.

Certain depositary receipts in which a Fund may invest are unsponsored, meaning that the depositary receipt is created and issued without the participation of the foreign issuer whose stock underlies the depositary receipt. The financial institution that issues an unsponsored depositary receipt may be under no obligation to distribute shareholder communications received from the foreign issuer or to pass through voting rights, and accordingly the holder of an unsponsored depositary receipt may not have as much current information concerning the foreign issuer as the holder of sponsored depositary receipt.

The considerations noted above generally are intensified for investments in developing countries, also known as emerging market countries, potentially including investments in issuers which are not domiciled in a developing country but which have reference to a significant percentage of their business in developing countries. Developing countries may have relatively unstable governments, economies based on only a few industries, and securities markets that trade a small number of securities.

Each of the Equity Funds, Summit Fund, Limited Term Income Fund, Ultra Short Income Fund, Core Plus Bond Fund, and Strategic Income Fund may conduct foreign currency transactions on a spot (i.e., cash) basis or by entering into forward contracts and futures contracts to purchase or sell foreign currencies at a future date and price. Additional detail about foreign currency transactions is provided below in the sections entitled “Investing in Derivative Instruments - Foreign Currency Transactions,” “Investing in Derivative Instruments - Futures Contracts - Futures Relating to Foreign Currencies,” “Investing in Derivative Instruments - Options - Options Relating to Foreign Currencies,” and “Investing in Derivative Instruments - Swap Agreements, Caps, Floors and Collars - Currency Swaps.”

A derivative instrument or derivatives transaction is a financial contract the value of which depends on, or is derived from, the value of some other underlying asset, reference rate, or index, such as equity securities, bonds, commodities, currencies, or interest rates. The use of derivative instruments may involve risks different from, or potentially greater than, the risks associated with investing directly in the underlying reference asset. In particular, the use by a Fund of privately negotiated, over-the-counter (“OTC”) derivatives contracts exposes the Fund to the risk that the counterparty to the OTC derivatives contract will be unable or unwilling to make timely payments under the contract or otherwise honor its obligations. Although Thornburg intends to monitor the creditworthiness of counterparties, there can be no assurance that a counterparty will meet its obligations, especially during periods of adverse market conditions. The market for certain types of derivative instruments may also be less liquid than the market for the underlying reference asset, making it difficult for a Fund to value its derivative investments or sell those investments at an acceptable price. Derivative instruments may also involve the risk that changes in their value may not correlate perfectly with the assets, rates or indices they are designed to track.

A Fund’s investment in derivative instruments may be limited by the requirements of Subchapter M of the Internal Revenue Code for qualification as a regulated investment company. See “Taxes.” A Fund’s investment in derivative instruments may also be limited to the extent Thornburg intends to continue to claim exclusion from the definition of “commodity pool operator” under the Commodity Exchange Act. See “Commodity Exchange Act Registration Exemption.”

The U.S. Securities and Exchange Commission (the “SEC”) has adopted rule 18f-4 of the 1940 Act related to the use of derivatives, short sales, reverse repurchase agreements and certain other transactions by registered investment companies, and in connection with the adoption of that rule, the SEC rescinded and withdrew certain previous guidance of the SEC and its staff regarding the use of asset segregation and cover transactions as a means to reduce the potential that a fund’s use of derivatives may constitute the issuance of “senior securities” by the fund. Rule 18f-4 requires a fund that enters into derivatives and certain other transactions which create future payment or delivery obligations (except reverse repurchase agreements and similar financing transactions) to be subject to a value-at-risk (“VaR”) leverage limit and certain derivatives risk management program and reporting requirements. Generally, these requirements apply unless the fund qualifies as a “limited derivatives user,” as defined in the rule. Under rule 18f-4, when a Fund trades reverse repurchase agreements or similar financing transactions it needs to aggregate the amount of indebtedness associated with those investments with the aggregate amount of any other senior securities representing indebtedness when calculating the Fund’s asset coverage ratio or treat all such transactions as derivatives transactions. Reverse repurchase agreements or similar financing transactions, including certain tender option bonds, aggregated with other indebtedness do not need to be included in the calculation of whether a fund is a limited derivatives user, but for funds subject to the VaR testing, reverse repurchase agreements and similar financing transactions must be included for purposes of such testing whether treated as derivatives transactions or not.

The Trust has adopted written policies and procedures to manage the derivatives risks of the Funds and comply with the requirements of rule 18f-4. Each Fund is currently classified as a limited derivatives user under rule 18f-4. As a limited derivatives user, each Fund’s derivatives exposure, excluding certain currency and interest rate hedging transactions, may not exceed 10% of its net assets. The Funds may exclude from treating as a derivative certain currency or interest rate derivatives that are not used for investment purposes but are instead are entered into and maintained by the fund for hedging purposes; and the notional amounts of such derivatives do not exceed the value of the hedged investments by more than 10%. Each Fund’s limit on its derivatives exposure of 10% of its net assets is not fundamental and may be changed by the Fund without a shareholder vote. If a Fund were to no longer be classified as a limited derivatives user, the more extensive requirements of rule 18f-4 which would then apply to the Fund may limit the ability of the Fund to use derivatives and reverse repurchase agreements and similar financing transactions as part of its investment strategies, and may also increase the cost of the Fund’s investments and cost of doing business, which could adversely affect investors.

The following discussion contains additional detail about the types of derivative instruments in which a Fund may invest and certain risks associated with those investments. You should also read the Prospectus for more information about derivative instruments and their risks.

option at one strike price and buying a call option at a lower price, in order to reduce the risk of the written call option in the event of a substantial price increase. Because combined options positions involve multiple trades, they result in higher transaction costs and may be more difficult to open and close out. A combined transaction will usually contain elements of risk that are present in each of its component transactions. Although combined transactions are normally entered into based on Thornburg’s judgment that the combined strategies will reduce risk or otherwise more effectively achieve the desired portfolio management goal, it is possible that the combination will instead increase such risks or hinder achievement of the goal.

Each of the Equity Funds, Summit Fund, Limited Term Income Fund, Ultra Short Income Fund, Core Plus Bond Fund, and Strategic Income Fund may make investments in Eurodollar instruments.

Eurodollar instruments are U.S. dollar-denominated futures contracts or options thereon which are linked to the London Interbank Offered Rate (“LIBOR”), although foreign currency-denominated instruments are available from time to time. Eurodollar futures contracts enable purchasers to obtain a fixed rate for the lending of funds and sellers to obtain a fixed rate for borrowings. A Fund might use Eurodollar futures contracts and options thereon to hedge against changes in the LIBOR, to which many interest rate swaps and fixed income instruments are linked.

The ICE Benchmark Administration Limited, the administrator of LIBOR, has ceased publishing certain LIBOR settings on December 31, 2021, and on June 30, 2023, while 1-, 3- and 6-month U.S. dollar LIBOR settings will continue to be published under an unrepresentative ‘synthetic’ methodology until September 30, 2024. After this, publication of LIBOR will cease permanently. However, there remains uncertainty regarding the future use of LIBOR and the nature of any replacement rates. Alternatives to LIBOR are established or in development in most major currencies, including the Secured Overnight Financing Rate (SOFR), that is intended to replace U.S. dollar LIBOR. SOFR is secured (collateralized by U.S. Treasuries), calculated by the Federal Reserve Bank of New York, and transactions based. Although the transition process away from LIBOR for most instruments has been completed, some LIBOR use is continuing and a Fund may invest in instruments that reference LIBOR. The transition process away from LIBOR may involve, among other things, increased volatility or illiquidity in markets for instruments that currently rely on LIBOR. The transition process may also result in a reduction in the value of certain instruments held by a Fund or reduce the effectiveness of related Fund transactions such as hedges. Volatility, the potential reduction in value, and/or the hedge effectiveness of financial instruments may be heightened for financial instruments that do not include fallback provisions that address the cessation of LIBOR. Any potential effects of the transition away from LIBOR on any of the Funds or on financial instruments in which a Fund invests, as well as other unforeseen effects, could result in losses to a Fund.

Conversions on a Spot Basis. A Fund may convert currency on a spot basis from time to time. Although foreign exchange dealers generally do not charge a fee for conversion, they do realize a profit based on the difference between the prices at which they are buying and selling various currencies. Thus, a dealer may offer to sell a foreign currency to a Fund at one rate, while offering a lesser rate of exchange should the Fund desire to resell that currency to the dealer.

Currency Forward Contracts. A currency forward contract is a privately negotiated obligation to purchase or sell a specific currency at a specific future date, at a price set at the time of the contract. The parties to a forward contract may agree to offset or terminate the contract before its maturity, or may hold the contract to maturity and complete the contemplated currency exchange. A Fund may use currency forward contracts for any purpose consistent with its investment objectives. The following discussion summarizes the principal currency management strategies involving forward contracts that could be used by a Fund. A Fund may also use swap agreements, indexed securities, and options and futures contracts relating to foreign currencies for the same purposes.

In those instances when a Fund enters into a forward currency contract, it typically does so for portfolio hedging purposes. In that regard, a Fund may enter into a forward contract to sell a foreign currency in which certain of its portfolio investments are denominated as a strategy to reduce the risk that a decline in the value of the foreign currency relative to the U.S. dollar will diminish the value of the portfolio investments denominated in that foreign currency. For example, if a Fund owned securities denominated in pounds sterling, it could enter into a forward contract to sell pounds sterling in return for U.S. dollars to hedge against possible declines in the pound’s value. Such a hedge, sometimes referred to as a “position hedge,” would tend to offset both positive and negative currency fluctuations, but would not offset changes in security values caused by other factors. A Fund could also hedge the position by selling another currency expected to perform similarly to the pound sterling. This type of hedge, sometimes referred to as a “proxy hedge,” could offer advantages in terms of cost, yield, or efficiency, but generally would not hedge currency exposure as effectively as a direct hedge into U.S. dollars. Proxy hedges may result in losses if the currency used to hedge does not perform similarly to the currency in which the hedged securities are denominated. A Fund could use a similar hedging strategy in an “indirect hedge” with respect to securities holdings that are denominated in U.S. dollars or another currency, but which conduct a substantial amount of business in a given foreign currency and are consequently exposed to a risk that the value of that foreign currency will decline relative to the U.S. dollar or other currency in which the holding is denominated. The Funds do not enter into hedging transactions in all instances when it might be desirable to do so, and any Fund may be exposed to currency risk some or most of the time without any hedging position for purposes of reducing that risk.

A Fund may also enter into forward contracts to shift investment exposure from one currency into another. This may include shifting exposure from U.S. dollars to a foreign currency, or from one foreign currency to another foreign currency. For example, if a Fund held investments denominated in pounds sterling, the Fund could enter into forward contracts to sell pounds sterling and purchase Swiss francs. This type of strategy, sometimes known as a “cross hedge,” will tend to reduce or eliminate exposure to the currency that is sold, and increase exposure to the currency that is purchased, much as if the Fund had sold a security denominated in one currency and purchased an equivalent security denominated in another. Cross-hedges protect against losses resulting from a decline in the hedged currency, but will cause a Fund to assume the risk of fluctuations in the value of the currency it purchases.

of U.S. dollars. This technique, sometimes referred to as a “settlement hedge” or “transaction hedge,” is intended to protect a Fund against an adverse change in foreign currency values between the date the security is purchased or sold and the date on which payment is made or received. A Fund also may enter into forward contracts to purchase or sell a foreign currency in anticipation of future purchases or sales of securities denominated in foreign currency, even if the specific investments have not yet been selected by Thornburg.

Currency transactions can result in losses to the Fund if the currency being hedged fluctuates in value to a degree or in a direction that is not anticipated. Further, there is the risk that the perceived linkage between various currencies may not be present or may not be present during the particular time that the Fund is engaged in a currency hedging transaction.

Because currency control is of great importance to the issuing governments and influences economic planning and policy, purchases and sales of currency and related instruments can be negatively affected by government exchange controls, blockages, and manipulations or exchange restrictions imposed by governments. Those can result in losses to a Fund if it is unable to deliver or receive currency in settlement of obligations and could also cause hedges it has entered into to be rendered ineffective, resulting in full currency exposure as well as incurring transaction costs. Currency futures are also subject to risks pertaining to futures contracts generally. See “Futures Contracts,” below. Options trading on currency futures is subject to market liquidity, and establishing and closing positions may be difficult. Currency exchange rates may fluctuate based on factors extrinsic to the issuing country’s own economy.

Successful use of currency management strategies will depend on Thornburg’s skill in analyzing and predicting currency values. Currency management strategies may substantially change a Fund’s investment exposure to changes in currency exchange rates, and could result in losses to the Fund if currencies do not perform as Thornburg anticipates. For example, if a currency’s value rose at a time when Thornburg had hedged a Fund’s exposure by selling that currency in exchange for dollars, the Fund would be unable to participate in the currency’s appreciation. If Thornburg hedges currency exposure through proxy hedges, a Fund could realize currency losses from the hedge and the security position at the same time if the two currencies do not move in tandem. Similarly, if Thornburg increases the Fund’s exposure to a foreign currency, and that currency’s value declines, the Fund will realize a loss. There is no assurance that Thornburg’s use of currency management strategies will be advantageous to a Fund or that it will hedge at an appropriate time.

Each of the Equity Funds, Summit Fund, Limited Term Income Fund, Ultra Short Income Fund, Core Plus Bond Fund, Strategic Income Fund, Short Duration Municipal Fund, and Strategic Municipal Income Fund may purchase or sell futures contracts to hedge against anticipated interest rate, currency or market changes, for duration management or risk management purposes, or to enhance potential income and gains.

When a Fund purchases a futures contract, it agrees to purchase a specified underlying instrument at a specified future date at a specified price. When a Fund sells a futures contract, it agrees to sell the underlying instrument at a specified future date at a specified price. Futures contracts are typically bought and sold on exchanges or boards of trade where the contracts are listed. Some currently available futures contracts are based on specific securities, such as U.S. Treasury bonds or notes, and some are based on indices of securities prices, such as the Standard & Poor’s 500 Composite Stock Price Index (“S&P 500”). Futures can be held until their delivery dates, or can be closed out before then if a liquid secondary market is available. The value of a futures contract tends to increase and decrease in tandem with the value of its underlying instrument. Therefore, purchasing futures contracts will tend to increase a Fund’s exposure to positive and negative price fluctuations in the underlying instrument, much as if it had purchased the underlying instrument directly. When a Fund sells a futures contract, by contrast, the value of its futures position will tend to move in a direction contrary to the market. Selling futures contracts, therefore will tend to offset both positive and negative market price changes, much as if the underlying instrument had been sold.

Distributions to shareholders associated with income or net gains realized by a Fund from transactions in futures contracts (or options on futures contracts) may be subject to federal income tax.

Liquidity of Futures Contracts. Some futures contracts may become illiquid under adverse market conditions, and there is no assurance that a liquid market will exist for any particular futures contract at any particular time. Exchanges and boards of trade may establish daily price fluctuation limits for options and futures contracts, and may halt trading if a contract’s price moves upward or downward more than the limit in a given day. On volatile trading days when the price fluctuation limit is reached or a trading halt is imposed, it may not be possible for a Fund to enter into new positions or to close out existing positions. If the market for a contract is not liquid because of price fluctuation limits or otherwise, it could prevent prompt liquidation of unfavorable positions, and potentially could require a Fund to continue to hold a position until expiration regardless of unfavorable changes in its value. In that instance, the Fund’s access to other assets that it has deposited to cover its futures positions also could be impaired.

Margin Payments. The purchaser or seller of a futures contract is not required to deliver or pay for the underlying instrument unless the contract is held until the delivery date. However, in any instance when a Fund enters into a futures contract, either as purchaser or as seller, the Fund will segregate with its custodian or with a futures commission merchant (“FCM”) as initial margin assets sufficient to meet its obligations under the contract. The Fund will also deposit daily “variation margin” payments as required during the term of the contract in order settle the change in the contract’s value on a daily basis (a process known as “marking to market”). Segregated assets may consist of cash, cash equivalents, high grade liquid debt obligations, or other assets agreed to by the parties to the futures contract. Initial and variation margin payments do not constitute purchasing securities on margin for purposes of a Fund’s investment limitations. In the event of the bankruptcy of a FCM that holds margin on behalf of a Fund, the Fund may be entitled to return of margin owed to it only in proportion to the amount received by the FCM’s other customers, potentially resulting in losses to the Fund.

Correlation of Price Changes. Because there are a limited number of types of futures contracts, it is likely that the standardized contracts available will not match a Fund’s current or anticipated investments exactly. A Fund may invest in futures contracts based on securities with different issuers, maturities, or other characteristics from the securities in which it typically invests, which involves a risk that the futures position will not track the performance of the Fund’s other investments. Futures prices can also diverge from the prices of their underlying instruments, even if the underlying instruments match the Fund’s investments well. Futures prices are affected by such factors as current and anticipated short-term interest rates, changes in volatility of the underlying instrument, and the time remaining until expiration of the contract, which may not affect security prices the same way. Imperfect correlation may also result from differing levels of demand in futures markets and the securities markets, from structural differences in how futures and securities are traded, or from imposition of daily price fluctuation limits or trading halts. A Fund may purchase or sell futures contracts with a greater or lesser value than the securities it wishes to hedge or intends to purchase in order to attempt to compensate for differences in volatility between

the contract and the securities, although this may not be successful in all cases. If price changes in the Fund’s futures positions are poorly correlated with its other investments, the positions may fail to produce anticipated gains or result in losses that are not offset by gains in other investments.

Futures Relating to Foreign Currencies. Currency futures contracts are similar to forward currency exchange contracts (see “Currency Forward Contracts” above), except that they are traded on exchanges (and have margin requirements) and are standardized as to contract size and delivery date. Most currency futures contracts call for payment or delivery in U.S. dollars.

The uses and risks of currency futures are similar to futures relating to other securities or indices. A Fund may purchase and sell currency futures to increase or decrease its exposure to different foreign currencies. A Fund also may purchase and write currency futures in conjunction with each other or with currency options or forward contracts. Currency futures values can be expected to correlate with exchange rates, but may not reflect other factors that affect the value of the Fund’s investments. A currency hedge, for example, should protect a Yen-denominated security from a decline in the Yen, but will not protect the Fund against a price decline resulting from deterioration in the issuer’s creditworthiness. Because the value of each Fund’s foreign-denominated investments changes in response to many factors other than exchange rates, it may not be possible to match the amount of currency futures to the value of the Fund’s investments exactly over time. See “Foreign Currency Transactions” above.

Each of the Equity Funds, Summit Fund, Core Plus Bond Fund, and Strategic Income Fund may purchase securities whose prices are indexed to the prices of other securities, securities indices, currencies, precious metals or other commodities or other financial indicators.

Indexed securities typically, but not always, are debt obligations or deposits whose value at maturity or coupon rate is determined by reference to a specific instrument or statistic. Gold-indexed securities, for example, typically provide for a maturity value that depends on the price of gold, resulting in a security whose price tends to rise and fall together with gold prices. Currency indexed securities typically are short-term to intermediate-term debt obligations whose maturity values or interest rates are determined by reference to the values of one or more specified foreign currencies, and may offer higher yields than U.S. dollar-denominated securities of equivalent issuers. Currency-indexed securities may be positively or negatively indexed; that is, their maturity value may increase when the specified currency value increases, resulting in a security that performs similarly to a foreign-denominated instrument, or their maturity value may decline when foreign currencies increases, resulting in a security whose price characteristics are similar to a put on the underlying currency. Currency-indexed securities may also have prices that depend on the values of a number of different foreign currencies relative to each other.

The performance of indexed securities depends to a great extent on the performance of the security, currency or other instrument to which they are indexed, and may also be influenced by interest rate changes in the U.S. and abroad. At the same time, indexed securities are subject to the credit risks associated with the issuer of the security, and their values may decline substantially if the issuer’s creditworthiness deteriorates. Recent issuers of indexed securities have included banks, corporations, and certain U.S. government agencies. Indexed securities may be more volatile than their underlying instruments.

Each of the Equity Funds, Summit Fund, Limited Term Income Fund, Ultra Short Income Fund, Core Plus Bond Fund, Strategic Income Fund, and Strategic Municipal Income Fund may purchase or write put and call options to hedge against anticipated interest rate or market changes, for duration management or risk management purposes, or to enhance potential income and gains.

Purchasing Put and Call Options. By purchasing a put option, a Fund obtains the right (but not the obligation) to sell the option’s underlying instrument at a fixed exercise or “strike” price. In return for this right, a Fund pays the current market price for the option (known as the option premium). Options have various types of underlying instruments, including specific equity securities or debt obligations, indices of securities prices, and futures contracts. A Fund may terminate its position in a put option it has purchased by allowing it to expire or by exercising the option. If the option is allowed to expire, the Fund will lose the entire premium it paid. If a Fund exercises the option, it completes the sale of the underlying instrument at the strike price. A Fund may also terminate a put option position by closing it out in the secondary market at its current price, if a liquid secondary market exists.

The buyer of a typical put option can expect to realize a gain if security prices fall substantially. However, if the underlying instrument’s price does not fall enough to offset the cost of purchasing the option, the owner of the put option will experience a loss measured by the premium paid to buy the option, plus related transaction costs.

The features of call options are similar to those of put options, except that the purchaser of a call option obtains the right to purchase, rather than sell, the underlying instrument at the option’s strike price. A call buyer typically attempts to participate in potential price increases of the underlying instrument with risk limited to the cost of the option if security prices fall. At the same time, the buyer will experience a loss if the underlying instrument’s price does not rise sufficiently to offset the buyer’s cost of purchasing the option and transaction costs.

The purchase of options increases a Fund’s costs because it must pay premiums to purchase the options, and the exercise of put and call options by a Fund will increase portfolio turnover and associated transaction costs. Because premiums for the purchase of options are typically much smaller than the prices to purchase the underlying instruments, the use of options creates leverage, which might result in a Fund’s net asset value being more sensitive to changes in the instruments underlying the options.

An American-style put or call option may be exercised at any time during the option period while a European-style put or call options may be exercised only upon expiration of the option period or during a fixed period prior thereto.

not be able to close out its position and would, therefore, remain obligated to purchase the underlying instrument at the strike price if the option is exercised. If the price of the underlying instrument rises, the writer of a put ordinarily will profit by the amount of the premium received on writing the option. If the price of the instrument declines, the writer may experience a loss, although the amount of the loss is offset to some degree by the amount of the premium received.

Writing a call option obligates the writer to sell or deliver the option’s underlying instrument, in return for the strike price, upon exercise of the option by the holder. The characteristics of writing call options are similar to those of writing put options, except that writing calls generally is a profitable strategy if prices remain the same or decline. Through receipt of the option premium, a Fund as the writer of such an option would seek to mitigate the effects of a decline in the price of the underlying instrument. At the same time, a Fund which writes an option must be prepared to deliver the underlying instrument in return for the strike price, even if the current value of the instrument is higher than the strike price. In that event, a Fund will experience a loss to the extent that the value of the underlying instrument exceeds the total of the strike price and the premium that it received when it wrote the option.

Exchange-Traded Options. Options may be traded on exchanges, or may be traded “over-the-counter” (see discussion of “OTC Options” below). Exchange-traded options are issued by a regulated intermediary, which guarantees the performance of the obligations of the parties to such options. With certain exceptions, exchange-traded options generally settle by physical delivery of the underlying security or currency, although in the future cash settlement may become available. Frequently, rather than taking or making delivery of the underlying instrument through the process of exercising the option, exchange-traded options are closed by entering into offsetting purchase or sale transactions that do not result in ownership of the new option.

A Fund’s ability to close out its position as a purchaser or seller of an exchange-traded option is dependent, in part, upon the liquidity of the option market. Among the possible reasons for the absence of a liquid option market on an exchange are: (i) insufficient trading interest in certain options; (ii) restrictions on transactions imposed by an exchange; (iii) trading halts, suspensions or other restrictions imposed with respect to particular classes or series of options or underlying securities including reaching daily price limits; (iv) interruption of the normal operations of the exchange; (v) inadequacy of the facilities of an exchange to handle current trading volume; or (vi) a decision by one or more exchanges to discontinue the trading of options (or a particular class or series of options), in which event the relevant market for that option on that exchange would cease to exist, although outstanding options on that exchange would generally continue to be exercisable in accordance with their terms.

The hours of trading for listed options may not coincide with the hours during which the underlying financial instruments are traded. To the extent that the option markets close before the markets for the underlying financial instruments, significant price and rate movements can take place in the underlying markets that cannot be reflected in the option markets.

OTC Options. Unlike exchange-traded options, which are standardized with respect to the underlying instrument, expiration date, contract size, and strike price, the terms of over-the-counter options generally are established through negotiation with the other party to the contract. While such arrangements allow greater flexibility to a Fund to tailor an option to its needs, “OTC” options generally involve greater credit risk than exchange-traded options, which are backed by the clearing organization of the exchange where they are traded. Accordingly, Thornburg must assess the creditworthiness of each counterparty or any guarantor or credit enhancement of the counterparty’s credit to determine the likelihood that the terms of the OTC option will be satisfied.

The staff of the SEC currently takes the position that OTC options are illiquid, and investments by each Fund in those instruments will be subject to each Fund’s limitation on investments in illiquid instruments. See “Illiquid Investments” below.

Limited Term Income Fund will engage in OTC option transactions only with United States government securities dealers recognized by the Federal Reserve Bank in New York as “primary dealers,” broker dealers, domestic or foreign banks or other financial institutions which have received a short-term credit rating of “A-1” from Standard & Poor’s Corporation or “P-1” from Moody’s Investor Services or have been determined by Thornburg to have an equivalent credit rating. Additionally, Limited Term Income Fund will only enter into OTC options that have a buy-back provision permitting the Fund to require the counterparty to buy back the option at a formula price within seven days. Limited Term Income Fund expects generally to enter into OTC options that have cash settlement provisions, although it is not required to do so.

Liquidity of Options. Some options become illiquid under adverse market conditions, and there is no assurance a liquid secondary market will exist for any particular options contract at any particular time. Options may have relatively low trading volume and liquidity if their strike prices are not close to the underlying instrument’s current price. In addition, exchanges may establish daily price fluctuation limits for options, and may halt trading if a contract’s price moves upward or downward more than the limit in a given day. On volatile trading days when the price fluctuation limit is reached or a trading halt is imposed, it may be impossible for a Fund to enter into new positions or close out existing positions. If the secondary market for a contract is not liquid because of price fluctuation limits or otherwise, it could prevent prompt liquidation of unfavorable positions, and potentially could require the Fund to continue to hold a position until delivery or expiration regardless of changes in its value. As a result, the Fund’s access to other assets held to cover its options positions could also be impaired.

Correlation of Price Changes. Because there are a limited number of types of exchange-traded options, it is likely that the standardized contracts available will not match a Fund’s current or anticipated investments exactly. A Fund may invest in options based on securities with different issuers, maturities, or other characteristics from the securities in which it typically invests, which involves a risk that the options position will not track the performance of the Fund’s other investments. Options prices can also diverge from the prices of their underlying instruments, even if the underlying instruments match the Fund’s investments well. Options prices are affected by such factors as current and anticipated short-term interest rates, changes in volatility of the underlying instrument, and the time remaining until expiration of the contract, which may not affect security prices the same way. Imperfect correlation may also result from differing levels of demand in the options markets and the securities markets, from structural differences in how options and securities are traded, or from imposition of daily price fluctuation limits or trading halts. A Fund may purchase or sell options contracts with a greater or lesser value than the securities it wishes to hedge or intends to purchase in order to attempt to compensate for differences in volatility between the contract and the securities, although this may not be successful in all cases. If price changes in the Fund’s options positions are poorly correlated with its other investments, the positions may fail to produce anticipated gains or result in losses that are not offset by gains in other investments.

Credit Options. Credit options are options whereby the purchaser has the right, but not the obligation, to enter into a transaction involving either an asset with inherent credit risk or a credit derivative, at terms specified at the inception of the option.

Options Relating to Foreign Currencies. The underlying instrument of a currency option may be a foreign currency, which generally is purchased or delivered in exchange for U.S. dollars, or may be a futures contract. The purchaser of a currency call obtains the right to purchase the underlying currency, and the purchaser of a currency put obtains the right to sell the underlying currency.

The uses and risks of currency options are similar to options relating to other securities or indices. A Fund may purchase and write currency options to increase or decrease its exposure to different foreign currencies. A Fund also may purchase and write currency options in conjunction with each other or with currency futures or forward contracts. Currency options values can be expected to correlate with exchange rates, but may not reflect other factors that affect the value of the Fund’s investments. A currency hedge, for example, should protect a Yen-denominated security from a decline in the Yen, but will not protect the Fund against a price decline resulting from deterioration in the issuer’s creditworthiness. Because the value of each Fund’s foreign-denominated investments changes in response to many factors other than exchange rates, it may not be possible to match the amount of currency options to the value of the Fund’s investments exactly over time. See “Foreign Currency Transactions” above.

Options on Futures Contracts. Options on futures contracts are similar to options on securities, except that an option on a futures contract gives the purchaser the right in return for the premium paid to assume a position in the underlying futures contract. If a Fund exercises an option on a futures contract it will be obligated to deposit initial margin (and potential subsequent variation margin) for the resulting futures position just as it would for any other futures contract position.

Options on Indices. Options on securities indices and other financial indices are similar to options on a security or other instrument except that, rather than settling by physical delivery of the underlying instrument, they settle by cash settlement (i.e., an option on an index gives the holder the right to receive, upon exercise of the option, an amount of cash if the closing level of the index upon which the option is based exceeds, in the case of a call, or is less than, in the case of a put, the exercise price of the option except if, in the case of an OTC option, physical delivery is specified). This amount of cash is equal to the excess of the closing price of the index over the exercise price of the option, which also may be multiplied by a formula value. The seller of the option is obligated, in return for the premium received, to make delivery of this amount. The gain or loss on an option on an index depends on price movements in the instruments making up the market, market segment, industry or other composite on which the underlying index is based rather than price movements in individual securities, as is the case with respect to options on securities.

Each of the Equity Funds, Summit Fund, Limited Term Income Fund, Ultra Short Income Fund, Core Plus Bond Fund, and Strategic Income Fund may invest in structured notes.

Structured notes are derivative debt obligations, the interest rate or principal of which is determined by reference to changes in the value of a specific asset, reference rate or index, or the relative change in two or more reference assets. The interest rate or the principal amount payable upon maturity or redemption may increase or decrease, depending upon changes in the value of the reference asset. The terms of a structured note may provide that, in certain circumstances, no principal is due at maturity and, therefore, may result in a loss of invested capital by a Fund. Structured notes may be indexed positively or negatively, so that appreciation of the reference asset may produce an increase or decrease in the interest rate or value of the principal at maturity. In addition, changes in the interest rate or the value of the principal at maturity may be fixed at a specified multiple of the change in the value of the reference asset, making the value of the note particularly volatile.

Structured notes may entail a greater degree of market risk than other types of debt obligations because the investor bears the risk of the reference asset. As noted above, the value of structured notes also may be more volatile than other debt obligations.

Each of the Equity Funds, Summit Fund, Limited Term Income Fund, Ultra Short Income Fund, Core Plus Bond Fund, Strategic Income Fund, and Strategic Municipal Income Fund may enter into swap agreements and related caps, floors and collars. None of these Funds are limited to any particular form of swap agreement, provided that Thornburg determines that the agreement it is consistent with the Fund’s investment objective and policies.

Swap agreements involve the exchange by a Fund and another party of their respective commitments to pay or receive cash flows. Although swaps can take a variety of forms, typically one party pays fixed and receives floating rate payments and the other party receives fixed and pays floating rate payments. Swap agreements can be individually negotiated and structured to include exposure to a variety of different types of investments or market factors. Swap agreements will tend to shift a Fund’s investment exposure from one type of investment to another. For example, if a Fund agreed to exchange payments in dollars for payments in foreign currency, the swap agreement would tend to decrease the Fund’s exposure to U.S. interest rates and increase its exposure to foreign currency and interest rates. Caps and floors have an effect similar to buying or writing options. Depending on how they are used, swap agreements may increase or decrease the overall volatility of a Fund’s investments and its share price and yield. The most significant factor in the performance of swap agreements is the change in the specific interest rate, currency, or other factors that determine the amounts of payments due to and from the Fund. If a swap agreement calls for payments by a Fund, the Fund must be prepared to make such payments when due. In addition, if the counterparty’s credit worthiness declined or if the counterparty defaults, the Fund will likely have contractual remedies available to it, but the value of the swap or other agreement would be likely to decline, potentially resulting in losses. Each Fund expects to be able to eliminate its exposure under swap agreements either by assignment or other disposition, or by entering into an offsetting swap agreement with the same party or a similarly creditworthy party.

Credit Default Swaps. A credit default swap is a credit derivative in which two parties enter into an agreement to transfer the credit exposure of fixed income securities. The buyer of credit protection (or seller of credit risk) agrees to pay the counterparty a fixed, periodic premium for a specified term. In return, the counterparty agrees to pay a contingent payment to the buyer in the event of an agreed upon credit occurrence which is typically a default by the issuer of a debt obligation.

Currency Swaps. A currency swap is an agreement to exchange cash flows on a notional amount of two or more currencies based on the relative value differential among them. Typically, the interest rates that determine the currency swap payments are fixed, although occasionally one or both parties may pay a floating rate of interest. Changes in foreign exchange rates and changes in interest rates may negatively affect the value of a currency swap.

Equity Swaps. In a typical equity swap, one party agrees to pay another party the return on a stock, stock index or basket of stocks in exchange for a specified interest rate. By entering into an equity index swap, for example, the index receiver can gain exposure to stocks making up the index of securities without actually purchasing those stocks. Equity index swaps involve not only the risks associated the investment in the securities represented in the index, but also the risk that the performance of such securities, including dividends, will not exceed the return on the interest rate that the Fund is committed to pay to the counterparty.

Interest Rate Swaps and Forward Rate Contracts. Interest rate swaps involve the exchange by the Fund with another party of their respective commitments to pay or receive interest, e.g., an exchange of fixed rate payments for floating rate payments. The Fund may also enter forward rate contracts. Under these contracts, the buyer locks in an interest rate at a future settlement date. If the interest rate on the settlement date exceeds the lock rate, the buyer pays the seller the difference between the two rates. Any such gain received by a Fund would be taxable. If the other party to an interest rate swap or forward rate contract defaults, a Fund’s risk of loss consists of the net amount of payments that the Fund is contractually entitled to receive. The net amount of the excess, if any, of the Fund’s obligations over its entitlements will be maintained in a segregated account by the Fund’s custodian. The Fund will not enter into any interest rate swap or forward rate contract unless the claims-paying ability of the other party thereto is considered satisfactory by Thornburg. If there is a default by the other party to such a transaction, the Fund will have contractual remedies pursuant to the agreements related to the transaction. These instruments are traded in the over-the-counter market.

Total Return Swaps. A total return swap is a credit derivative in which the buyer receives a periodic return equal to the total economic return of a specified security, securities or index, for a specified period of time. In return, the buyer pays the counterparty a variable stream of payments, typically based upon short-term interest rates, possibly plus or minus an agreed upon spread.

Caps, Floors and Collars. The purchase of a cap entitles the purchaser to receive payments on a notional principal amount from the party selling the cap to the extent that a specified index exceeds a predetermined interest rate or amount. For example, an interest rate cap is an agreement between two parties over a specified period of time where one party makes payments to the other party equal to the difference between the current level of an interest rate index and the level of the cap, if the specified interest rate index increases above the level of the cap. The purchase of a floor entitles the purchaser to receive payments on a notional principal amount from the party selling the floor to the extent that a specified index falls below a predetermined interest rate or amount. For example, an interest rate floor is similar except the payments are the difference between the current level of an interest rate index and the level of the floor if the specified interest rate index decreases below the level of the floor. A collar is a combination of a cap and a floor that preserves a certain return within a predetermined range of interest rates or values. For example, an interest rate collar is the simultaneous execution of a cap and floor agreement on a particular interest rate index.

The Summit Fund may invest in commodities-related investments, including equity and debt securities issued by companies that operate commodities-based businesses, commodity futures contracts or other commodity-linked derivative instruments, and exchange traded funds or other investment vehicles that invest in commodities. The prices of commodities-related investments may move in different directions than investments in other equity and debt securities when the value of those other securities is declining due to adverse economic conditions. As an example, during periods of rising inflation, debt securities have historically tended to decline in value due to the general increase in prevailing interest rates. Conversely, during those same periods of rising inflation, the prices of certain commodities, such as oil and metals, have historically tended to increase. Of course, there cannot be any guarantee that these investments will perform in that manner in the future, and at certain times the price movements of commodities-related investments have been parallel to those of debt and equity securities. Commodities have historically tended to increase and decrease in value during different parts of the business cycle than financial assets. Nevertheless, at various times, commodities prices may move in tandem with the prices of financial assets and thus may not provide overall portfolio diversification benefits. Under favorable economic conditions, the Summit Fund’s commodities-related investments may be expected to underperform an investment in traditional securities. Over the long term, the returns on the Summit Fund’s commodities-related investments may be expected to exhibit low or negative correlation with stocks and bonds.

Additionally, to the extent the Summit Fund obtains exposure to commodities through the use of commodity futures contracts or other derivatives, those derivatives may involve risks different or greater than the risks affecting the underlying assets. See “Investing in Derivatives,” above.

The following contains additional detail about certain other investments a Fund may make and certain other risks to which a Fund may be subject.

Consideration of Environmental, Social and Governance (“ESG”) Characteristics

When evaluating a potential investment opportunity, each of the Funds may consider the issuer’s ESG characteristics, however, only the Thornburg Better World International Fund considers the issuer’s ESG characteristics as a principal investment strategy. Thornburg defines a significant ESG characteristic as one which may materially affect an issuer’s risk and return profile and, accordingly, the issuer’s long-term investment performance. In this way, Thornburg’s consideration of ESG characteristics is no different than its consideration of more traditional financial metrics or other factors which may affect the risks and returns of a Fund’s investments. The specific ESG characteristics which Thornburg determines to be significant will vary over time and among different financial sectors and industries, but will generally include environmental, social capital, human capital, business model and innovation, and leadership and governance characteristics. Examples of potentially significant environmental characteristics include: greenhouse gas emissions; air quality; energy management; water and wastewater management; waste and hazardous materials management; and ecological impacts. Examples of potentially significant social capital characteristics include: human rights and community relations; customer privacy; data security; access & affordability; product quality and safety; customer welfare; and selling practice and product labeling. Examples of potentially significant human capital characteristics include: labor practices; employee health & safety; and employee engagement, diversity and inclusion. Examples of potentially significant business model and innovation characteristics include: product design and lifecycle management; business model resilience; supply chain management; materials sourcing and efficiency; and the physical impacts of climate change. Examples of potentially significant leadership and governance characteristics include: business ethics; competitive behavior; management of the legal and regulatory environment; critical risk management; and systemic risk management.

While Thornburg makes its own judgments about the ESG characteristics of each Fund’s investments, Thornburg’s approach may be informed by third party data and other research tools, including consideration of the list of material ESG factors established by the Sustainability Accounting Standards Board.

There are no universally agreed upon objective standards for assessing ESG characteristics, and they can vary over different periods and evolve over time. Certain ESG characteristics are subjective and can be difficult to analyze, and the evaluation of ESG characteristics frequently involves assessing various risks relating to the financial stability and sustainability of an investment, and ESG characteristics may not always be reflected in third party data. ESG characteristics may also be difficult to apply consistently across regions, countries, industries, or sectors. Given the absence of generally accepted criteria, investors and others may disagree as what constitutes a significant ESG characteristic, or may otherwise assign a greater or lesser emphasis than Thornburg to a particular ESG characteristic. In addition, there may be situations where Thornburg determines that an issuer has been identified by Thornburg as having both positive and negative ESG characteristics. For example, an issuer may extract or use fossil fuels in a manner which may contribute to negative environmental outcomes, but that same issuer is making investments to prepare for a transition to cleaner sources of energy. In those instances, Thornburg may consider as part of its investment analysis how both the positive and negative ESG characteristics are likely to affect the issuer’s long-term investment performance.

Each Fund except Limited Term U.S. Government Fund, Limited Term Municipal Fund, Limited Term California Fund, Intermediate New Mexico Fund, Intermediate New York Fund, and Intermediate Municipal Fund may also invest a portion or all of the Fund’s daily cash balance in Thornburg Capital Management Fund, a separate series of the Trust (the “Capital Management Fund”). The Capital Management Fund’s shares are not publicly available. The Capital Management Fund is not a money market fund and does not seek to maintain a stable net asset value of $1.00. The Capital Management Fund seeks current income consistent with liquidity management and safety of capital. To pursue that investment objective, the Capital Management Fund invests principally in short-term obligations which are determined by Thornburg to be of high quality including, but not limited to, obligations issued by U.S. and foreign companies, U.S. and foreign banks, U.S. and foreign governments, U.S. agencies, states, and municipalities, and international organizations such as the World Bank and the International Monetary Fund, and repurchase agreements based on those obligations. The Capital Management Fund does not currently pay a separate investment advisory fee or administrative services fee to Thornburg, but Funds which invest in the Capital Management Fund would indirectly bear the other operating expenses of the Capital Management Fund. Those indirect expenses are similar to the expenses paid by other businesses owned by the Funds, are not direct costs paid by Fund shareholders, are not used to calculate a Fund’s net asset value, and have no impact on the costs associated with Fund operations.

Each Fund may under certain circumstances purchase bank certificates of deposit. Each Municipal Fund may invest in certificates of deposit of domestic banks with assets of $1 billion or more as part of the Fund’s permitted “temporary investments” (see “Temporary Investments” below). Limited Term U.S. Government Fund may invest up to 20% of its assets in: (i) certificates of deposit maturing in one year or less after the date of acquisition and issued by domestic banks with assets of $1 billion or more; and (ii) certificates of deposit insured as to principal by the Federal Deposit Insurance Corporation. If any certificate of deposit in which Limited Term U.S. Government Fund invests (whether or not insured in whole or in part) is nonnegotiable and matures in more than seven days, the certificate of deposit will be deemed by Limited Term U.S. Government Fund to be illiquid and will, therefore, be subject to the Fund’s investment restriction respecting investment in illiquid investments. Limited Term Income Fund may invest in certificates of deposit of domestic and foreign banks with assets of $1 billion or more, including foreign branches of domestic banks. Limited Term Income Fund and Ultra Short Income Fund may also invest in certificates of deposit issued by banks and savings and loan institutions with assets of less than $1 billion, provided that (i) the principal amounts of such certificates of deposit are insured by an agency of the U.S. Government, (ii) at no time will the Fund hold more than $100,000 principal amount of certificates of deposit of any one such bank, and (iii) at the time of acquisition, no more than 10% of the Fund’s assets (taken at current value) are invested in certificates of deposit of such banks. Each of the Equity Funds and Strategic Income Fund may invest in certificates of deposit issued by domestic and foreign banks, including foreign branches of domestic banks.

Investments in certificates of deposit issued by foreign banks or foreign branches of domestic banks involves investment risks that are different in some respects from those associated with investment in certificates of deposit issued by domestic banks. (See “Foreign Investments” above).

As the use of technology has become more prevalent, the Funds and their service providers have become potentially more susceptible to intentional and unintentional cyber events including, but not limited to: computer processing errors; malfunctions, disruptions, or failures in computer systems or other technologies; computer viruses; the theft or corruption of electronic data; unauthorized access to digital systems; and cyber attacks that shut down, disable or otherwise disrupt business operations. These events may adversely affect the Funds or their shareholders, causing disruptions in business operations and potentially resulting in financial losses. For example, a cyber attack against the computer systems of the Funds or their service providers may interfere with the ability to process Fund shareholder transactions or to calculate a Fund’s net asset value, impede trading activity by the Funds, result in the release or misappropriation of confidential information about the Funds or their shareholders, or subject the Funds to regulatory fines or penalties and to other, additional costs (including increased costs to remediate the effects of the attack or to develop additional systems to prevent other similar attacks). While the Funds and Thornburg have established procedures and systems to seek to prevent and mitigate the risks associated with cyber events, and while Thornburg seeks to determine that other third party service providers for the Funds have established such procedures and systems, there are inherent limitations in the ability of such procedures and systems to identify all potential cyber events or to completely prevent or mitigate the occurrence or effects of those events. Additionally, cyber events affecting the electronic systems of the Funds’ trading counterparties, issuers in which the Funds invest, or securities markets and exchanges may also result in financial losses for the Funds or their shareholders.

Each of the Equity Funds, Summit Fund Limited Term U.S. Government Fund, Limited Term Income Fund, Ultra Short Income Fund, Core Plus Bond Fund, Strategic Income Fund may enter into “dollar roll” transactions.

Dollar roll transactions consist of the sale by a Fund to a bank or broker-dealer (the “counterparty”) of Ginnie Mae certificates or other mortgage-backed securities together with a commitment to purchase from the counterparty similar, but not identical, securities at a future date at the same price. The counterparty receives all principal and interest payments, including prepayments, made on the security while it is the holder. The selling Fund receives a fee from the counterparty as consideration for entering into the commitment to purchase. Dollar rolls may be renewed over a period of several months with a new purchase and repurchase price fixed and a cash settlement made at each renewal without physical delivery of securities. Moreover, the transaction may be preceded by a firm commitment agreement pursuant to which a Fund agrees to buy a security on a future date.

Dollar rolls are currently treated for purposes of the 1940 Act as borrowings of the Fund entering into the transaction because they involve the sale of a security coupled with an agreement to repurchase, and are, therefore, deemed by the Trust to be subject to the investment restrictions applicable to any borrowings made by the Fund. Like all borrowings, a dollar roll involves costs to the borrowing Fund. For example, while the borrowing Fund receives a fee as consideration for agreeing to repurchase the security, the Fund forgoes the right to receive all principal and interest payments while the counterparty holds the security. These payments to the counterparty may exceed the fee received by the Fund, thereby effectively charging the Fund interest on its borrowing. Further, although the Fund can estimate the amount of expected principal prepayment over the term of the dollar roll, a variation in the actual amount of prepayment could increase or decrease the cost of the Fund’s borrowing.

Dollar rolls involve potential risks of loss to the selling Fund which are different from those related to the securities underlying the transactions. For example, if the counterparty becomes insolvent, the Fund’s right to purchase from the counterparty may be restricted. Additionally, the value of such securities may change adversely before a Fund is able to purchase them. Similarly, the selling Fund may be required to purchase securities in connection with a dollar roll at a higher price than may otherwise be available on the open market. Since, as noted above, the counterparty is required to deliver a similar, but not identical security to the Fund, the security which the Fund is required to buy under the dollar roll may be worth less than an identical security. Finally, there can be no assurance that a Fund’s use of the cash that it receives from a dollar roll will provide a return that exceeds borrowing costs.

Illiquid investments are investments that cannot be sold or disposed of in the ordinary course of business at approximately the prices at which they are valued. Under the supervision of the Trustees, Thornburg determines the liquidity of investments by the Funds. In determining the liquidity of the Funds’ investments, Thornburg may consider various factors, including (1) the frequency of trades and quotations, (2) the number of dealers and prospective purchasers in the marketplace, (3) dealer undertakings to make a market, (4) the nature of the security (including any demand or lender features), and (5) the nature of the market place for trades (including the ability to assign or offset each Fund’s rights and obligations relating to the investment).

Investments currently considered by Thornburg to be illiquid include repurchase agreements not entitling the holder to payment of principal and interest within seven days, over-the-counter options, and municipal lease obligations subject to non-appropriation risk where the underlying lease is not rated (at the time the obligation is purchased by the Fund) within the four highest grades of Moody’s or S&P and is not subject to a remarketing agreement (or not currently subject to remarketing, pursuant to the conditions of any such agreement then in effect, with a responsible remarketing party, deemed by Thornburg to be capable of performing its obligations) except that Thornburg also may determine an unrated lease obligation to be readily marketable because it is backed by an irrevocable bank letter of credit or an insurance policy. Based on its ongoing review of the trading markets and other factors affecting the Funds’ investments, Thornburg may determine from time to time that other investments are illiquid, including certain types of restricted securities, mortgage-backed securities and asset-backed securities, developing country securities, or derivative instruments. With respect to any over-the-counter options that a Fund writes, all or a portion of the value of the underlying instrument may be illiquid depending on the assets held to cover the option and the nature and terms of any agreement the Fund any have to close out the option before expiration. In the absence of market quotations, illiquid investments are priced at fair value as determined utilizing procedures approved by the Trustees.

Each Fund is limited from investing more than a certain percentage of its net assets in illiquid investments. Please see “Investment Restrictions” below for a discussion of the specific limitations applicable to each Fund’s investment in illiquid investment s. If through a change in values, net assets, or other circumstances, a Fund were in a position where the percentage of its portfolio comprised of illiquid investments exceeded that Fund’s percentage investment restriction on investment in illiquid investments, the Fund would seek to take appropriate steps to protect liquidity.

The Summit Fund may be subject to inflation and deflation risk. Inflation risk is the risk that the present value of assets or income of a Fund will be worth less in the future as inflation decreases the present value of money. The Summit Fund’s dividend rates or borrowing costs, where applicable, may also increase during periods of inflation. This may further reduce Summit Fund performance. Deflation risk is the risk that prices throughout the economy decline over time creating an economic recession, which could make issuer default more likely and may result in a decline in the value of the Summit Fund’s assets. Generally, securities issued in emerging markets are subject to a greater risk of inflationary or deflationary forces, and more developed markets are better able to use monetary policy to normalize markets. If at any time the rate of inflation exceeds Thornburg’s expectations, or if for other reasons the Summit Fund’s portfolio is unsuccessful in producing a total return that exceeds the rate of inflation, the Summit Fund may not achieve its goal.

Each Fund may enter into repurchase agreements. Each of the Municipal Funds may only enter into repurchase agreements with respect to taxable securities constituting “temporary investments” in the Fund’s portfolio (see “Temporary Investments” herein), and no Municipal Fund will enter into a repurchase agreement if, as a result, more than 5% of the value of the Fund’s net assets would be invested in repurchase agreements.

In a repurchase agreement, a Fund purchases a security and simultaneously commits to resell that security to the seller at an agreed upon price on an agreed upon date within a number of days from the date of purchase. The resale price reflects the purchase price plus an agreed upon incremental amount which is unrelated to the coupon rate or maturity of the purchased security. A repurchase agreement involves the obligation of the seller to pay the agreed upon price, which obligation is in effect secured by the value (at least equal to the amount of the agreed upon resale price and marked to market daily) of the underlying security. The Fund may engage in repurchase agreements with respect to any security in which it is authorized to invest.

A Fund may enter into these arrangements with member banks of the Federal Reserve System or any domestic broker-dealer if the creditworthiness of the bank or broker-dealer has been determined by Thornburg to be satisfactory. These transactions may not provide the Fund with collateral marked-to-market during the term of the commitment.

A repurchase agreement may be viewed as a loan from a Fund to the seller of the security subject to the repurchase agreement. It is not clear whether a court would consider the security purchased by the Fund subject to a repurchase agreement as being owned by the Fund or as being collateral for a loan by the Fund to the seller. In the event of the commencement of bankruptcy or insolvency proceedings with respect to the seller of the security before repurchase of the security under a repurchase agreement, the Fund may encounter delay and incur costs before being able to sell the security. Delays may involve loss of interest or decline in the price of the underlying security. If the court characterized the transaction as a loan and the Fund has not perfected a security interest in the underlying security, the Fund may be required to return the security to the seller’s estate and be treated as an unsecured creditor of principal and income involved in the transaction. As with any unsecured debt obligation purchased for the Fund, Thornburg seeks to minimize the risk of loss through repurchase agreements by analyzing the creditworthiness of the obligor, in this case the seller of the security. Apart from the risk of bankruptcy or insolvency proceedings, there is also the risk that the seller may fail to repurchase the security, in which case the Fund may incur a loss if the proceeds to the Fund of the sale to a third party are less than the repurchase price. However, if the market value (including interest) of the security subject to the repurchase agreement becomes less than the repurchase price (including interest), the Fund will direct the seller of the security to deliver additional securities so that the market value (including interest) of all securities subject to the repurchase agreement will equal or exceed the repurchase price. It is possible that the Fund will be unsuccessful in seeking to impose on the seller a contractual obligation to deliver additional securities.

Restricted securities generally can be sold in privately negotiated transactions, pursuant to an exemption from registration under the 1933 Act, or in a registered public offering. Where registration is required, a Fund could be obligated to pay all or part of the registration expense and a considerable period may elapse between the time it decides to seek registration and the time it is permitted to sell a security under an effective registration statement. If, during such a period, adverse market conditions were to develop, the Fund might obtain a less favorable price than prevailed when it decided to seek registration of the security. A restricted security may be liquid or illiquid, depending on whether it satisfies relevant liquidity requirements, as determined by Thornburg. See “Illiquid Investments” above.

Each of the Equity Funds, Summit Fund, Limited Term U.S. Government Fund, Limited Term Income Fund, Ultra Short Income Fund, Core Plus Bond Fund, Strategic Income Fund, and Strategic Municipal Income Fund may enter into reverse repurchase agreements. Neither Limited Term U.S. Government Fund nor Limited Term Income will enter into a reverse repurchase agreement if, as a result, more than 5% of the Fund’s total assets would then be subject to reverse repurchase agreements.

In a reverse repurchase agreement, a Fund sells a portfolio instrument to another party, such as a bank or broker-dealer, in return for cash and agrees to repurchase the instrument at a particular price and time. While a reverse repurchase agreement is outstanding, the Fund will maintain appropriate liquid assets in a segregated custodial account to cover its obligation under the agreement. A Fund will enter into reverse repurchase agreements only with parties whose creditworthiness has been found satisfactory by Thornburg. Such transactions may increase fluctuations in the market value of the Funds’ assets and may be viewed as a form of leverage.

Each of the Equity Funds, Summit Fund, Limited Term U.S. Government Fund, Limited Term Income Fund, Ultra Short Income Fund, Core Plus Bond Fund, and Strategic Income Fund may lend securities to parties such as broker-dealers or institutional investors. Securities lending allows a Fund to retain ownership of the securities loaned and, at the same time, to earn additional income. Since there may be delays in the recovery of loaned securities, or even a loss of rights in collateral supplied should the borrower fail financially, loans will be made only to parties deemed by Thornburg to be of good standing. Furthermore, they will only be made if, in Thornburg’s judgment, the consideration to be earned from such loans would justify the risk.

Thornburg understands that it is the current view of the SEC Staff that a Fund may engage in loan transactions only under the following conditions: (1) the Fund must receive 100% collateral in the form of cash or cash equivalents (e.g., U.S. Treasury bills or notes) from the borrower; (2) the borrower must increase the collateral whenever the market value of the securities loaned (determined on a daily basis) rises above the value of the collateral; (3) after giving notice, the Fund must be able to terminate the loan at any time; (4) the Fund must receive reasonable interest on the loan or a flat fee from the borrower, as well as amounts equivalent to any dividends, interest, or other distributions on the securities loaned and to any increase in market value; (5) the Fund may pay only reasonable custodian fees in connection with the loan; and (6) the Trustees must be able to vote proxies on the securities loaned, either by terminating the loan or by entering into an alternative arrangement with the borrower.

Cash received through loan transactions may be invested in any security in which a Fund is authorized to invest. Investing this cash subjects that investment, as well as the security loaned, to market forces (i.e., capital appreciation or depreciation).

Each Fund may from time to time invest a keep a portion of its portfolio in cash or other short-term, fixed income securities. Such investments may be made due to market conditions, pending investment of idle funds, or to afford liquidity.

In particular, each Municipal Fund, except for Limited Term Municipal Fund which has no limit, has reserved the right to invest up to 20% of its assets in “temporary investments” in taxable securities that would produce interest not exempt from federal income tax. See “Taxes.” These investments are limited to the following short-term, fixed-income securities (maturing in one year or less from the time of purchase): (i) obligations of the United States government or its agencies, instrumentalities or authorities; (ii) prime commercial paper within the two highest ratings of Moody’s or S&P; (iii) certificates of deposit of domestic banks with assets of $1 billion or more; and (iv) repurchase agreements with respect to the foregoing types of securities. Repurchase agreements will be entered into by the Municipal Funds only with dealers, domestic banks or recognized financial institutions that, in Thornburg’s opinion, represent

minimal credit risk. Investments in repurchase agreements are limited to 5% of a Municipal Fund’s net assets. Temporary taxable investments may exceed 20% of a Fund’s assets when made for defensive purposes during periods of abnormal market conditions.

Each Fund may purchase securities offered on a “when-issued” or “delayed delivery” basis. When-issued and delayed delivery transactions arise when securities are purchased or sold with payment and delivery beyond the regular settlement date. When-issued transactions normally settle within 30-45 days, though the settlement cycles for some when-issued transactions are longer. On such transactions the payment obligation and the interest rate are fixed at the time the buyer enters into the commitment. The commitment to purchase securities on a when-issued or delayed delivery basis may involve an element of risk because the value of the securities is subject to market fluctuation, no interest accrues to the purchaser prior to settlement of the transaction, and at the time of delivery the market value may be less than the purchase price. Additionally, purchasing securities on a when-issued or delayed delivery basis involves the risks that the security will never be issued or that the other party to the transaction will not meet its obligation, in which events the Fund may lose any gain in that security’s price. At the time a Fund makes the commitment to purchase a security on a when-issued or delayed delivery basis, it will record the transaction and reflect the value of the security in determining its net asset value. Pursuant to current SEC guidance, a transaction involving a when-issued security will not be deemed to involve a senior security as long as the Fund intends to settle the transaction physically and the transaction settles within 35 days. While when-issued or delayed delivery securities may be sold prior to the settlement date, it is intended that the Fund will purchase such securities with the purpose of actually acquiring them unless sale appears desirable for investment reasons. If a when-issued security is sold before delivery any gain or loss would not be tax-exempt.

In connection with its management of the Trust, Thornburg has filed a notice of eligibility for exclusion from the definition of the term “commodity pool operator” in accordance with Rule 4.5 under the U.S. Commodity Exchange Act, as amended (the “CEA”) and, therefore, neither Thornburg nor the Trust is currently subject to registration or regulation as a commodity pool operator under the CEA. The U.S. Commodity Futures Trading Commission (“CFTC”) recently adopted amendments to Rule 4.5 under the CEA that reduce the ability of certain regulated entities, including registered investment companies and their investment advisors, to claim the exclusion from the definition of the term “commodity pool operator.” Among other requirements, the CFTC’s amendments impose limitations on the use of certain derivative instruments, including certain types of commodity futures contracts, commodity options contracts, and swaps, by entities seeking to rely on Rule 4.5. Thornburg currently intends to manage the Funds’ assets in a manner which is consistent with the limitations imposed by Rule 4.5. To the extent Thornburg or the Funds became no longer eligible to claim an exclusion from the definition of the term “commodity pool operator,” then Thornburg or some or all of the Funds may become subject to registration and regulation under the CEA. Such regulation may have an adverse effect on Thornburg’s ability to manage the Funds, may impair the ability of the Funds to achieve their investment objective(s), and may result in higher operating expenses for the Funds and reduced investment returns to Fund investors.

The following policies and limitations supplement those set forth in the Prospectus. Unless otherwise noted, whenever an investment policy or limitation states a maximum percentage of a Fund’s assets that may be invested in any security or other asset, that percentage limitation will be determined immediately after and as a result of the Fund’s acquisition of such security or other asset. Accordingly, any subsequent change in values, net assets, or other circumstances will not be considered when determining whether the investment complies with the Fund’s investment policies and limitations. For those policies and limitations which can only be changed by a majority of a Fund’s outstanding voting shares, the term “majority” means the lesser of (i) 67% of the shares of the Fund present in person or by proxy at a meeting of the holders of more than 50% of the Fund’s outstanding shares, or (ii) more than 50% of the outstanding shares of the Fund.

Global Opportunities Fund, International Equity Fund, International Growth Fund, Small/Mid Cap Core Fund, Small/Mid Cap Growth Fund, Investment Income Builder Fund, and Strategic Income Fund

Thornburg Investment Trust has adopted the following fundamental investment policies applicable to Global Opportunities Fund, International Equity Fund, International Growth Fund, Small/Mid Cap Core Fund, Small/Mid Cap Growth Fund, Investment Income Builder Fund, and Strategic Income Fund, which may not be changed by any Fund unless approved by a majority of the outstanding shares of that Fund. Global Opportunities Fund, International Equity Fund, International Growth Fund, Small/Mid Cap Core Fund, Small/Mid Cap Growth Fund, Investment Income Builder Fund, and Strategic Income Fund may not:

(1) with respect to 75% of the Fund’s total assets, purchase the securities of any issuer (other than securities issued or guaranteed by the U.S. government or any of its agencies or instrumentalities) if, as a result, (a) more than 5% of the Fund’s total assets would be invested in the securities of that issuer, or (b) the Fund would hold more than 10% of the outstanding voting securities of that issuer;

(3) borrow money, except for temporary or emergency purposes or except in connection with reverse repurchase agreements; in an amount not exceeding 33 1/3% of its total assets (including the amount borrowed) less liabilities (other than borrowings). Any borrowings that come to exceed this amount will be reduced within three days (not including Sundays and holidays) to the extent necessary to comply with the 33 1/3 % limitation;

(4) underwrite any issue of securities (except to the extent that the Fund may be deemed to be an underwriter within the meaning of the 1933 Act in the disposition of restricted securities);

(5) purchase the securities of any issuer (other than securities issued or guaranteed by the U.S. government or any of its agencies or instrumentalities) if, as a result, more than 25% of the Fund’s total assets would be invested in the securities of companies whose principal business activities are in the same industry;

(6) purchase or sell real estate unless acquired as a result or ownership of securities or other instruments (but this shall not prevent the Fund from investing in securities or other instruments backed by real estate or securities of companies engaged in the real estate business);

(7) purchase or sell physical commodities unless acquired as a result of ownership of securities or other instruments (but this shall not prevent the Fund from purchasing or selling options and futures contracts or from investing in securities or other instruments backed by physical commodities); or

(8) lend any security or make any other loan if, as a result, more than 33 1/3% of its total assets would be lent to other parties, but this limitation does not apply to purchases of debt securities or to repurchase agreements.

Each Fund’s limitation on investing more than 25% of the Fund’s total assets in the same industry, as described in paragraph (5) above, also applies to investments in the same group of industries. In determining whether an issuer should be classified in a particular industry or industry group for purposes of that limitation, Thornburg may rely on its own analysis of the issuer or on available third party industry classifications. The limitation on investing in industries and industry groups does not apply to an investment by the Fund in a particular economic sector, such as the utilities, hospital and healthcare facilities, or industrial development sectors. Additionally, securities of the U.S. Government and its agencies and instrumentalities are not considered to represent industries for this purpose.

For the purposes of applying the limitation set forth in paragraph (6) above, a Fund is permitted to hold real estate if doing so is the result of the Fund’s efforts to restructure a bond or other loan obligation that was secured by real estate.

The following investment limitations are not fundamental and may be changed without shareholder approval as to each Fund:

(ii) The Fund does not currently intend to purchase securities on margin, except that the Fund may obtain such short-term credits as are necessary for the clearance of transactions, and provided that any initial and variation margin payments that the Fund may be required to make in connection with its permitted investment strategies do not constitute the purchase of securities “on margin” for purposes of this limitation.

(iii) The Fund may borrow money only (a) from a bank or (b) by engaging in reverse repurchase agreements with any party. The Fund will not purchase any security while borrowings representing more than 5% of its total assets are outstanding.

(iv) The Fund does not currently intend to purchase any security if, as a result, more than 15% of its net assets would be invested in securities that are deemed to be illiquid because they are subject to legal or contractual restrictions on resale or because they cannot be sold or disposed of in the ordinary course of business at approximately the prices at which they are valued.

(v) The Fund does not currently intend to purchase interests in real estate investment trusts that are not readily marketable or interests in real estate limited partnerships that are not listed on an exchange or traded on the NASDAQ National Market System if, as a result, the sum of such interests and other investments considered illiquid under the limitation in the preceding paragraph would exceed the Fund’s limitations on investments in illiquid investments.

(vi) The Fund does not currently intend to (a) purchase securities of other investment companies, except in the open market where no commission except the ordinary broker’s commission is paid, or (b) purchase or retain securities issued by other open-end investment companies. Limitations (a) and (b) do not apply to the Fund’s investments in Thornburg Capital Management Fund or in any other investment company within the same “group of investment companies” (as defined in Section 12(d)(1)(G) of the 1940 Act), provided that any such investments comply with Section 12(d)(1)(G) of the 1940 Act and rules thereunder, or to securities received as dividends, through offers of exchange, or as a result of a reorganization, consolidation, or merger.

(vii) The Fund does not currently intend to purchase the securities of any issuer (other than securities issued or guaranteed by domestic or foreign governments or political subdivisions thereof) if, as a result, more than 5% of its total assets would be invested in the securities of business enterprises that, including predecessors, have a record of less than three years of continuous operation. The foregoing does not apply to the Fund’s investments in Thornburg Capital Management Fund or in any other investment company within the same “group of investment companies” (as defined in Section 12(d)(1)(G) of the 1940 Act); provided that any such investments will comply with Section 12(d)(1)(G) of the 1940 Act and rules thereunder.

(viii) The Fund does not currently intend to purchase warrants, valued at the lower of cost or market, in excess of 5% of the Fund’s net assets. Included in that amount, but not to exceed 2% of the Fund’s net assets, may be warrants that are not listed on the New York Stock Exchange or the American Stock exchange. Warrants acquired by the Fund in units or attached to securities are not subject to these restrictions.

(ix) The Fund does not currently intend to invest in oil, gas or other mineral exploration or development programs or leases.

(x) The Fund does not currently intend to purchase the securities of any issuer if those officers and Trustees of the trust and those officers and directors of Thornburg who individually own more than 1/2 of 1% of the securities of such issuer together own more than 5% of such issuer’s securities.

(xi) The Fund will not (a) sell futures contracts, purchase put options, or write call options if, as a result, more than 25% of the Fund’s total assets would be hedged with futures and options under normal conditions; (b) purchase futures contracts or write put options if, as a result, the Fund’s total obligations upon settlement or exercise of purchased futures contracts and written put options would exceed 25% of its total assets; or (c) purchase call options if, as a result, the current value of option premiums for call options purchased by the Fund would exceed 5% of the Fund’s total assets. These limitations do not apply to options attached to or acquired or traded together with their underlying securities, and do not apply to securities that incorporate features similar to options.

Thornburg Investment Trust has adopted the following fundamental investment policies applicable to Better World International Fund which may not be changed unless approved by a majority of the outstanding shares of the Fund. Better World International Fund may not:

(3) borrow money, except for temporary or emergency purposes or except in connection with reverse repurchase agreements; in an amount not exceeding 33 1/3 % of its total assets (including the amount borrowed) less liabilities (other than borrowings). Any borrowings that come to exceed this amount will be reduced within three days (not including Sundays and holidays) to the extent necessary to comply with the 33 1/3 % limitation;

(4) underwrite any issue of securities (except to the extent that the Fund may be deemed to be an underwriter within the meaning of the 1933 Act in the disposition of restricted securities);

(7) purchase or sell physical commodities unless acquired as a result of ownership of securities or other instruments (but this shall not prevent the Fund from purchasing or selling options, futures contracts and other derivative instruments or from investing in securities or other instruments backed by physical commodities); or

(8) lend any security or make any other loan if, as a result, more than 33 1/3 % of its total assets would be lent to other parties, but this limitation does not apply to lending of portfolio securities, purchases of debt securities or other instruments, or to repurchase agreements.

The Fund’s limitation on investing more than 25% of the Fund’s total assets in the same industry, as described in paragraph (5) above, also applies to investments in the same group of industries. In determining whether an issuer should be classified in a particular industry or industry group for purposes of that limitation, Thornburg may rely on its own analysis of the issuer or on available third party industry classifications. The limitation on investing in industries and industry groups does not apply to an investment by the Fund in a particular economic sector, such as the utilities, hospital and healthcare facilities, or industrial development sectors. Additionally, securities of the U.S. Government and its agencies and instrumentalities are not considered to represent industries for this purpose.

For the purposes of applying the limitation set forth in paragraph (6) above, the Fund is permitted to hold real estate if doing so is the result of the Fund’s efforts to restructure a bond or other loan obligation that was secured by real estate.

The following investment limitations are not fundamental and may be changed without shareholder approval as to the Fund:

(v) The Fund will not (a) sell futures contracts, purchase put options, or write call options if, as a result, more than 25% of the Fund’s total assets would be hedged with futures and options under normal conditions; (b) purchase futures contracts or write put options if, as a result, the Fund’s total obligations upon settlement or exercise of purchased futures contracts and written put options would exceed 25% of its total assets; or (c) purchase call options if, as a result, the current value of option premiums for call options purchased by the Fund would exceed 5% of the Fund’s total assets. These limitations do not apply to options attached to or acquired or traded together with their underlying securities, and do not apply to securities that incorporate features similar to options.

Thornburg Investment Trust has adopted the following fundamental investment policies applicable to Developing World Fund which may not be changed unless approved by a majority of the outstanding shares of the Fund. Developing World Fund may not:

(3) underwrite any issue of securities (except to the extent that the Fund may be deemed to be an underwriter within the meaning of the 1933 Act in the disposition of portfolio securities);

(4) purchase or sell real estate unless acquired as a result or ownership of securities or other instruments (but this shall not prevent the Fund from investing in securities or other instruments backed by real estate or securities of companies engaged in the real estate business, nor shall it prevent the Fund from holding real estate as a result of the Fund’s efforts to restructure a bond or other investment that was backed by real estate);

(5) purchase or sell physical commodities unless acquired as a result of ownership of securities or other instruments (but this shall not prevent the Fund from purchasing or selling options, futures contracts and other derivative instruments or from investing in securities or other instruments backed by physical commodities);

(6) lend any security or make any other loan if, as a result, more than 33 1/3% of its total assets would be lent to other parties, but this limitation does not apply to lending of portfolio securities, purchases of debt obligations or other instruments, or to repurchase agreements; or

(7) with respect to 75% of the Fund’s total assets, purchase the securities of any issuer (other than securities issued or guaranteed by the U.S. government or any of its agencies or instrumentalities) if, as a result, (a) more than 5% of the Fund’s total assets would be invested in the securities of that issuer, or (b) the Fund would hold more than 10% of the outstanding voting securities of that issuer.

In connection with the restriction in paragraph (2), above, the 1940 Act currently permits an investment company to borrow money if the borrowings do not exceed one-third of the company’s total assets after subtracting liabilities other than the borrowings.

The following investment limitations are not fundamental and may be changed without shareholder approval; provided that the first investment limitation listed below may only be changed to the extent that the Fund’s Trustees provide 60 days’ prior written notice of the change to the Fund’s shareholders:

(i) The Fund will invest at least 80% of its assets (which, for this purpose, refers to the net assets of the Fund plus the amount of any borrowings) in developing country issuers, as defined in the Fund’s Prospectus;

(ii) The Fund does not currently intend to sell securities short, unless it owns or has the right to obtain securities equivalent in kind and amount to the securities sold short, and provided that transactions in futures contracts and options are not deemed to constitute selling securities short.

(iii) The Fund does not currently intend to purchase securities on margin, except that the Fund may obtain such short-term credits as are necessary for the clearance of transactions, and provided that any initial and variation margin payments that the Fund may be required to make in connection with its permitted investment strategies do not constitute the purchase of securities “on margin” for purposes of this limitation.

(iv) The Fund may borrow money only (a) from a bank or (b) by engaging in transactions that are deemed to be borrowings under the 1940 Act because they involve the sale of a security coupled with an agreement to repurchase that security. The Fund will not purchase any security while borrowings representing more than 5% of its total assets are outstanding.

(v) The Fund does not currently intend to purchase any security if, as a result, more than 15% of its net assets would be invested in securities that are considered by Thornburg to be illiquid because they are subject to legal or contractual restrictions on resale or because they cannot be sold or disposed of in the ordinary course of business at approximately the prices at which they are valued.

(vi) The Fund will not (a) sell futures contracts, purchase put options, or write call options if, as a result, more than 25% of the Fund’s total assets would be hedged with futures and options under normal conditions; (b) purchase futures contracts or write put options if, as a result, the Fund’s total obligations upon settlement or exercise of purchased futures contracts and written put options would exceed 25% of its total assets; or (c) purchase call options if, as a result, the current value of option premiums for call options purchased by the Fund would exceed 5% of the Fund’s total assets. These limitations do not apply to options attached to or acquired or traded together with their underlying securities, and do not apply to securities that incorporate features similar to options.

Thornburg Investment Trust has adopted the following fundamental investment policies applicable to the Summit Fund which may not be changed unless approved by a majority of the outstanding shares of the Fund. The Summit Fund may not:

(2) borrow money, except for temporary or emergency purposes or except in connection with reverse repurchase agreements; in an amount not exceeding 33 1 /3% of its total assets (including the amount borrowed) less liabilities (other than

borrowings). Any borrowings that come to exceed this amount will be reduced within three days (not including Sundays and holidays) to the extent necessary to comply with the 33 1 /3% limitation;

(3) underwrite any issue of securities (except to the extent that the Fund may be deemed to be an underwriter within the meaning of the Securities Act of 1933 in the disposition of restricted securities);

(4) purchase the securities of any issuer (other than securities issued or guaranteed by the U.S. government or any of its agencies or instrumentalities) if, as a result, more than 25% of the Fund’s total assets would be invested in the securities of companies whose principal business activities are in the same industry;

(6) purchase or sell physical commodities unless acquired as a result of ownership of securities or other instruments (but this shall not prevent the Fund from purchasing or selling options, futures contracts and other derivative instruments or from investing in securities or other instruments backed by physical commodities, or as otherwise permitted by (i) the 1940 Act and the rules and regulations thereunder, as amended from time to time); or

(7) lend any security or make any other loan if, as a result, more than 33 1 /3% of its total assets would be lent to other parties, but this limitation does not apply to lending of portfolio securities, purchases of debt securities or other instruments, or to repurchase agreements.

The Fund’s limitation on investing more than 25% of the Fund’s total assets in the same industry, as described in paragraph (4) above, also applies to investments in the same group of industries. In determining whether an issuer should be classified in a particular industry or industry group for purposes of that limitation, Thornburg may rely on its own analysis of the issuer or on available third party industry classifications. The limitation on investing in industries and industry groups does not apply to an investment by the Fund in a particular economic sector, such as the utilities, hospital and healthcare facilities, or industrial development sectors. Additionally, for purposes of applying the limitation described in paragraph (4) above, issuers of the following securities will not be considered to be members of any industry: securities of the U.S. Government and its agencies and instrumentalities; municipal obligations the income from which is exempt from the regular federal income tax; and repurchase agreements collateralized by such obligations. Notwithstanding the foregoing, to the extent that the income from a municipal obligation is derived principally from the assets and revenues of non-governmental users, the obligation will be deemed to have been issued from the industry of that non-governmental user. The views and interpretations by the Fund stated in this paragraph may change due to changes in the law or interpretations of the law, including laws pertaining to municipal obligations and the taxability of interest paid on those obligations, and due to other factors.

For the purposes of applying the limitation set forth in paragraph (5) above, the Fund is permitted to hold real estate if doing so is the result of the Fund’s efforts to restructure a bond or other loan obligation that was secured by real estate. References above to the 1940 Act and the Securities Act of 1933 include in each case any rules, exemptions or interpretations of those statutes that may be adopted, granted or issued by the SEC.

The following investment limitations are not fundamental and may be changed without shareholder approval as to the Fund:

(i) The Fund does not currently intend to purchase securities on margin, except that the Fund may obtain such short-term credits as are necessary for the clearance of transactions, and provided that the Fund may use margin to the extent necessary to engage in short sales, and provided that any initial and variation margin payments that a Fund may be required to make in connection with its permitted investment strategies do not constitute the purchase of securities “on margin” for purposes of this limitation.

(ii) The Fund may borrow money only (a) from a bank or (b) by engaging in reverse repurchase agreements with any party. The Fund will not purchase any security while borrowings representing more than 5% of its total assets are outstanding.

(iii) The Fund does not currently intend to purchase any security if, as a result, more than 15% of its net assets would be invested in securities that are deemed to be illiquid because they are subject to legal or contractual restrictions on resale or because they cannot be sold or disposed of in the ordinary course of business at approximately the prices at which they are valued.

(iv) The Fund will not (a) sell futures contracts, purchase put options, or write call options if, as a result, more than 25% of the Fund’s total assets would be hedged with futures and options under normal conditions; (b) purchase futures contracts or write put options if, as a result, the Fund’s total obligations upon settlement or exercise of purchased futures contracts and written put options would exceed 25% of its total assets; or (c) purchase call options if, as a result, the current value of option premiums for call options purchased by the Fund would exceed 5% of the Fund’s total assets. These limitations do not apply to options attached to or acquired or traded together with their underlying securities, and do not apply to securities that incorporate features similar to options.

Thornburg Investment Trust has adopted the following fundamental investment policies applicable to Limited Term U.S. Government Fund which may not be changed unless approved by a majority of the outstanding shares of the Fund. Limited Term U.S. Government Fund may not:

(1) Invest more than 20% of the Fund’s assets in securities other than obligations issued or guaranteed by the United States Government or its agencies, instrumentalities and authorities, or in participations in such obligations or repurchase agreements secured by such obligations, generally described (but not limited) in the Prospectus, and then only in the nongovernmental obligations described in the Prospectus;

(2) Purchase any security if, as a result, more than 5% of its total assets would be invested in securities of any one issuer, excluding obligations of, or guaranteed by, the United States government, its agencies, instrumentalities and authorities;

10% of the Fund’s total assets. The exceptions to this restriction are not for investment leverage purposes but are solely for extraordinary or emergency purchases or to facilitate management of the Fund’s portfolio by enabling the Fund to meet redemption requests when the liquidation of portfolio instruments is deemed to be disadvantageous. The Fund will not purchase securities while borrowings are outstanding. For purposes of this restriction (i) the security arrangements described in restriction (4) below will not be considered as borrowing money, and (ii) reverse repurchase agreements will be considered as borrowing money;

(4) Mortgage, pledge or hypothecate any assets except to secure permitted borrowings. Arrangements to segregate assets with the Fund’s custodian with respect to when-issued and delayed delivery transactions, and reverse repurchase agreements, and deposits made in connection with futures contracts, will not be considered a mortgage, pledge or hypothecation of assets;

(5) Underwrite any issue of securities, except to the extent that, in connection with the disposition of portfolio securities, it may be deemed to be an underwriter under federal securities laws;

(6) Purchase or sell real estate and real estate mortgage loans, but this shall not prevent the Fund from investing in obligations of the U.S. Government or its agencies, relating to real estate mortgages as described generally in the Prospectus;

(7) Purchase or sell commodities or commodity futures contracts or oil, gas or other mineral exploration or development programs. Investment in futures contracts respecting securities and in options on these futures contracts will not be considered investment in commodity futures contracts;

(8) Make loans, except through (a) the purchase of debt obligations in accordance with the Fund’s investment objectives and policies; (b) repurchase agreements with banks, brokers, dealers and other financial institutions; and (c) loans of securities;

(9) Purchase any security on margin, except for such short-term credits as are necessary for the clearance of transactions. For purposes of this restriction, the Fund’s entry into futures contracts will not be considered the purchase of securities on margin;

(11) Invest more than 5% of its total assets in securities of unseasoned issuers which, together with their predecessors, have been in operation for less than three years excluding obligations of, or guaranteed by, the United States government, its agencies, instrumentalities and authorities;

(12) Invest more than 5% of its total assets in securities which the Fund is restricted from selling to the public without registration under the 1933 Act. The Fund has no present intention to purchase any such restricted securities;

(13) Purchase securities of any issuer if the purchase at the time thereof would cause more than 10% of the voting securities or more than 10% of any class of securities of any such issuer to be held by the Fund;

(14) Purchase securities of other investment companies, except in connection with a merger, consolidation, reorganization or acquisition of assets;

(15) Purchase securities (other than securities of the United States government, its agencies, instrumentalities and authorities) if, as a result, more than 25% of the Fund’s total assets would be invested in any one industry;

(16) Purchase or retain the securities of any issuer other than the securities of the Fund if, to the Fund’s knowledge, those officers and Trustees of the Fund, or those officers and directors of Thornburg, who individually own beneficially more than 1/2 of 1% of the outstanding securities of such issuer, together own beneficially more than 5% of such outstanding securities;

(17) Enter into any reverse repurchase agreement if, as a result thereof, more than 5% of its total assets would be subject to its obligations under reverse purchase agreements at any time;

(18) Purchase or sell any futures contract if, as a result thereof, the sum of the amount of margin deposits on the Fund’s existing futures positions and the amount of premiums paid for related options would exceed 5% of the Fund’s total assets;

(20) Purchase the securities of any issuer if as a result more than 10% of the value of the Fund’s net assets would be invested in securities which are considered illiquid because they are subject to legal or contractual restrictions on resale (“restricted securities”) or because no market quotations are readily available; or enter into a repurchase agreement maturing in more than seven days, if as a result such repurchase agreements together with restricted securities and securities for which there are no readily available market quotations would constitute more than 10% of the Fund’s net assets; or

(21) Issue senior securities, as defined under the 1940 Act, except that the Fund may enter into repurchase agreements and reverse repurchase agreements, lend its portfolio securities, borrow, and enter into when-issued and delayed delivery transactions as described in the Prospectus or this Statement of Additional Information and as limited by the foregoing investment limitations.

Whenever an investment policy or restriction states a minimum or maximum percentage of the Fund’s assets which may be invested in any security or other assets, it is intended that the minimum or maximum percentage limitations will be determined immediately after and as a result of the Fund’s acquisition of the security or asset. Accordingly, any later increase or decrease in the relative percentage of value represented by the asset or security resulting from changes in asset values will not be considered a violation of these restrictions.

In applying the percentage restrictions on the Fund’s investments described under the caption “Principal Investment Strategies” in the Prospectus, and in applying the restriction described in paragraph (1), above, “assets” is understood to mean net assets plus borrowings for investment purposes.

For the purposes of applying the limitation set forth in paragraph (9) above, any initial and variation margin payments that a Fund may be required to make in connection with its permitted investment strategies do not constitute the purchase of securities “on margin.”

The Fund’s limitation on investing more than 25% of the Fund’s total assets in the same industry, as described in paragraph (15) above, also applies to investments in the same group of industries. In determining whether an issuer should be classified in a particular industry or industry group for purposes of that limitation, Thornburg may rely on its own analysis of the issuer or on available third party industry classifications. The limitation on investing in industries and industry groups does not apply to an investment by the Fund in a particular economic sector, such as the utilities, hospital and healthcare facilities, or industrial development sectors. Additionally, securities of the U.S. Government and its agencies and instrumentalities are not considered to represent industries for this purpose.

Although the Fund has the right to pledge, mortgage or hypothecate its assets subject to the restrictions described above, in order to comply with certain state statutes on investment restrictions, the Fund will not, as a matter of operating policy (which policy may be changed by the Trustees without shareholder approval), mortgage, pledge or hypothecate its portfolio securities to the extent that at any time the percentage of pledged securities will exceed 10% of its total assets.

Thornburg Investment Trust has adopted the following fundamental investment policies applicable to Limited Term Income Fund which may not be changed unless approved by a majority of the outstanding shares of the Fund. Limited Term Income Fund may not:

(1) with respect to 75% of its total assets taken at market value, purchase more than 10% of the voting securities of any one issuer or invest more than 5% of the value of its total assets in the securities of any one issuer, except obligations issued or guaranteed by the U.S. Government, its agencies or instrumentalities and except securities of other investment companies;

(2) borrow money, except as a temporary measure for extraordinary or emergency purposes or except in connection with reverse repurchase agreements; provided that the Fund maintains asset coverage of 300% for all borrowings;

(3) purchase or sell real estate (except that the Fund may invest in (i) securities of companies which deal in real estate or mortgages, and (ii) securities secured by real estate or interests therein and that the Fund reserves freedom of action to hold and sell real estate acquired as a result of the Fund’s ownership of securities) or purchase or sell physical commodities or contracts relating to physical commodities;

(4) act as underwriter of securities issued by others, except to the extent that it may be deemed an underwriter in connection with the disposition of portfolio securities of the Fund;

(5) make loans to any other person, except (a) loans of portfolio securities, and (b) to the extent that the entry into repurchase agreements and the purchase of debt securities in accordance with its investment objectives and investment policies may be deemed to be loans;

(6) issue senior securities, except as appropriate to evidence indebtedness which it is permitted to incur, and except for shares of the separate classes of a fund or series of the Trust provided that collateral arrangements with respect to currency-related contracts, futures contracts, options, or other permitted investments, including deposits of initial and variation margin, are not considered to be the issuance of senior securities for purposes of this restriction;

(7) purchase any securities which would cause more than 25% of the market value of its total assets at the time of such purchase to be invested in the securities of one or more issuers having their principal business activities in the same industry, provided that there is no limitation with respect to investments in obligations issued or guaranteed by the U.S. government or its agencies or instrumentalities (for the purposes of this restriction, telephone companies are considered to be in a separate industry from gas and electric public utilities, and wholly-owned finance companies are considered to be in the industry of their parents if their activities are primarily related to financing the activities of the parents).

For the purposes of applying the limitation set forth in paragraph (3) above, the Fund is permitted to hold real estate if doing so is the result of the Fund’s efforts to restructure a bond or other loan obligation that was secured by real estate.

The Fund’s limitation on investing more than 25% of the Fund’s total assets in the same industry, as described in paragraph (7) above, also applies to investments in the same group of industries. In determining whether an issuer should be classified in a particular industry or industry group for purposes of that limitation, Thornburg may rely on its own analysis of the issuer or on available third party industry classifications. The limitation on investing in industries and industry groups does not apply to an investment by the Fund in a particular economic sector, such as the utilities, hospital and healthcare facilities, or industrial development sectors. Additionally, securities of the U.S. Government and its agencies and instrumentalities are not considered to represent industries for this purpose.

The following investment limitations are not fundamental and may be changed without shareholder approval:

(a) The Fund does not currently intend to purchase or retain securities of any open-end investment company, or securities of any closed-end investment company except by purchase in the open market where no commission or profit to a sponsor or dealer results from such purchases, or except when such purchase, though not made in the open market, is part of a plan of merger, consolidation, reorganization or acquisition of assets. The Fund will not acquire any security issued by another investment company (the “acquired company”) if the Fund thereby would own (i) more than 3% of the total outstanding voting securities of the acquired company, or (ii) securities issued by the acquired company having an aggregate value exceeding 5% of the Fund’s total assets, or (iii) securities issued by investment companies having an aggregate value exceeding 10% of the Fund’s total assets. The limitations stated in this subparagraph (a) do not apply to the Fund’s investments in Thornburg Capital Management Fund or in any other investment company within the same “group of investment companies” (as defined in Section 12(d)(1)(G) of the 1940 Act); provided that any such investments will comply with Section 12(d)(1)(G) of the 1940 Act and rules thereunder.

(b) The Fund will not pledge, mortgage or hypothecate its assets in excess, together with permitted borrowings, of 1/3 of its total assets.

(c) The Fund does not currently intend to purchase or retain securities of an issuer any of whose officers, directors, trustees or security holders is an officer or Trustee of the Fund or a member, officer, director or trustee of the investment advisor of the Fund if one or more of such individuals owns beneficially more than one-half of one percent (1/2%) of the outstanding shares or securities or both (taken at market value) of such issuer and such shares or securities together own beneficially more than 5% of such shares or securities or both.

(d) The Fund does not currently intend to purchase securities on margin or make short sales, unless, by virtue of its ownership of other securities, it has the right to obtain securities equivalent in kind and amount to the securities sold and, if the right is conditional, the sale is made upon the same conditions, except in connection with arbitrage transactions, and except that the Fund may obtain such short-term credits as may be necessary for the clearance of purchases and sales of securities. Any initial and variation margin payments that the Fund may be required to make in connection with its permitted investment strategies do not constitute the purchase of securities “on margin” for purposes of this limitation.

(e) The Fund does not currently intend to purchase any security if, as a result, more than 15% of its net assets would be invested in securities that are considered by Thornburg to be illiquid because they are subject to legal or contractual restrictions on resale or because they cannot be sold or disposed of in the ordinary course of business at approximately the prices at which they are valued.

(f) The Fund does not currently intend to purchase securities of any issuers with a record of less than three years of continuous operations, including predecessors, except U.S. government securities, securities of such issuers which are rated by at least one nationally recognized statistical rating organization, municipal obligations and obligations issued or guaranteed by any foreign government or its agencies or instrumentalities, if such purchase would cause the investments of the Fund in all such issuers to exceed 5% of the total assets of the Fund taken at market value. The foregoing does not apply to the Fund’s investments in Thornburg Capital Management Fund or in any other investment company within the same “group of investment companies” (as defined in Section 12(d) (1)(G) of the 1940 Act); provided that any such investments will comply with Section 12(d)(1)(G) of the 1940 Act and rules thereunder.

(g) The Fund does not currently intend to purchase more than 10% of the voting securities of any one issuer, except securities issued by the U.S. Government, its agencies or instrumentalities. The foregoing does not apply to the Fund’s investments in Thornburg Capital Management Fund or in any other investment company within the same “group of investment companies” (as defined in Section 12(d)(1)(G) of the 1940 Act); provided that any such investments will comply with Section 12(d)(1)(G) of the 1940 Act and rules thereunder.

(h) The Fund will not buy options on securities or financial instruments, unless the aggregate premiums paid on all such options held by the Fund at any time do not exceed 20% of its net assets; or sell put options in securities if, as a result, the aggregate value of the obligations underlying such put options would exceed 50% of the Fund’s net assets.

(i) The Fund will not enter into futures contracts or purchase options thereon unless immediately after the purchase, the value of the aggregate initial margin with respect to all futures contracts entered into on behalf of the Fund and the premiums paid for options on futures contracts does not exceed 5% of the fair market value of the Fund’s total assets; provided that in the case of an option that is in-the-money at the time of purchase, the in-the-money amount may be excluded in computing the 5% limit.

(j) The Fund does not currently intend to invest more than 5% of its assets in derivative instruments, although this limitation will not apply to investments in derivative instruments made by the Fund for bona fide hedging or risk management purposes.

(k) The Fund does not currently intend to invest in oil, gas or other mineral leases, or exploration or development programs (although it may invest in issuers which own or invest in such interests).

(l) The Fund will not borrow money except as a temporary measure, and then not in excess of 5% of its total assets (taken at market value) unless the borrowing is from banks, in which case the percentage limitation is 10%; reverse repurchase agreements and dollar rolls will be considered borrowings for this purpose, and will be further subject to total asset coverage of 300% for such agreements.

(m) The Fund does not currently intend to purchase warrants if as a result warrants taken at the lower of cost or market value would represent more than 5% of the value of the Fund’s total net assets or more than 2% of its net assets in warrants that are not listed on the New York or American Stock Exchanges or on an exchange with comparable listing requirements (for this purpose, warrants attached to securities will be deemed to have no value).

(n) The Fund will not make securities loans if the value of such securities loaned exceeds 30% of the value of the Fund’s total assets at the time any loan is made; all loans of portfolio securities will be fully collateralized and marked to market daily. The Fund has no current intention of making loans of portfolio securities that would amount to greater than 5% of the Fund’s total assets.

(o) The Fund does not currently intend to purchase or sell real estate limited partnership interests.

Restrictions with respect to repurchase agreements shall be construed to be for repurchase agreements entered into for the investment of available cash consistent with Limited Term Income Fund’s repurchase agreement procedures, not repurchase commitments entered into for general investment purposes.

Thornburg Investment Trust has adopted the following fundamental investment policies applicable to the Ultra Short Income Fund, which may not be changed by the Fund unless approved by a majority of the outstanding shares of that Fund. The Fund may not:

(4) underwrite any issue of securities (except to the extent that the Fund may be deemed to be an underwriter within the meaning of the 1933 Act in the disposition of restricted securities);

The following investment limitations are not fundamental and may be changed without shareholder approval as to the Fund:

(i) The Fund does not currently intend to sell securities short, unless it owns or has the right to obtain securities equivalent in kind and amount to the securities sold short, and provided that any initial and variation margin payments that the Fund may be required to make in connection with its permitted investment strategies do not constitute the purchase of securities “on margin” for purposes of this limitation.

(ii) The Fund does not currently intend to purchase securities on margin, except that the Fund may obtain such short-term credits as are necessary for the clearance of transactions, and provided that margin payments in connection with futures contracts and options on futures contracts shall not constitute purchasing securities on margin.

(v) The Fund does not currently intend to (a) purchase securities of other investment companies, except in the open market where no commission except the ordinary broker’s commission is paid, or (b) purchase or retain securities issued by other open-end investment companies. Limitations (a) and (b) do not apply to the Fund’s investments in Thornburg Capital Management Fund or in any other investment company within the same “group of investment companies” (as defined in Section 12(d)(1)(G) of the 1940 Act), provided that any such investments comply with Section 12(d)(1)(G) of the 1940 Act and rules thereunder, or to securities received as dividends, through offers of exchange, or as a result of a reorganization, consolidation, or merger.

(vi) The Fund does not currently intend to purchase the securities of any issuer (other than securities issued or guaranteed by domestic or foreign governments or political subdivisions thereof) if, as a result, more than 5% of its total assets would be invested in the securities of business enterprises that, including predecessors, have a record of less than three years of continuous operation. The foregoing does not apply to the Fund’s investments in Thornburg Capital Management Fund or in any other investment company within the same “group of investment companies” (as defined in Section 12(d)(1)(G) of the 1940 Act); provided that any such investments will comply with Section 12(d)(1)(G) of the 1940 Act and rules thereunder.

(vii) The Fund does not currently intend to purchase warrants, valued at the lower of cost or market, in excess of 5% of the Fund’s net assets. Included in that amount, but not to exceed 2% of the Fund’s net assets, may be warrants that are not listed on a national securities exchange. Warrants acquired by the Fund in units or attached to securities are not subject to these restrictions.

(viii) The Fund does not currently intend to invest in oil, gas or other mineral exploration or development programs or leases.

(ix) The Fund does not currently intend to purchase the securities of any issuer if those officers and Trustees of the trust and those officers and directors of Thornburg who individually own more than 1/2 of 1% of the securities of such issuer together own more than 5% of such issuer’s securities.

(x) The Fund will not (a) sell futures contracts, purchase put options, or write call options if, as a result, more than 25% of the Fund’s total assets would be hedged with futures and options under normal conditions; (b) purchase futures contracts or write put options if, as a result, the Fund’s total obligations upon settlement or exercise of purchased futures contracts and written put options would exceed 25% of its total assets; or (c) purchase call options if, as a result, the current value of option premiums for call options purchased by the Fund would exceed 5% of the Fund’s total assets. These limitations do not apply to options attached to or acquired or traded together with their underlying securities, and do not apply to securities that incorporate features similar to options.

Thornburg Investment Trust has adopted the following fundamental investment policies applicable to Core Plus Bond Fund which may not be changed by any Fund unless approved by a majority of the outstanding shares of the Fund. The Fund may not:

(3) borrow money, except in an amount not exceeding 33 1/3% of its total assets (including the amount borrowed) less liabilities (other than borrowings). Any borrowings that come to exceed this amount will be reduced within three days (not including Sundays and holidays) to the extent necessary to comply with the 33 1/3 % limitation;

(4) underwrite any issue of securities (except to the extent that the Fund may be deemed to be an underwriter within the meaning of the 1933 Act in the disposition of restricted securities);

(5) purchase or sell real estate unless acquired as a result or ownership of securities or other instruments (but this shall not prevent the Fund from investing in securities or other instruments backed by real estate or securities of companies engaged in the real estate business, nor shall it prevent the Fund from holding real estate as a result of the Fund’s efforts to restructure a bond or other loan obligation that was secured by real estate);

(7) lend any security or make any other loan if, as a result, more than 33 1/3% of its total assets would be lent to other parties, but this limitation does not apply to lending of portfolio securities, purchases of debt obligations or other instruments purchases of debt securities or to repurchase agreements; or

The Fund’s limitation on investing more than 25% of the Fund’s total assets in the same industry, as described in paragraph (8) above, also applies to investments in the same group of industries. In determining whether an issuer should be classified in a particular industry or industry group for purposes of that limitation, Thornburg may rely on its own analysis of the issuer or on available third party industry classifications. The limitation on investing in industries and industry groups does not apply to an investment by the Fund in a particular economic sector, such as the utilities, hospital and healthcare facilities, or industrial development sectors. Additionally, securities of the U.S. Government and its agencies and instrumentalities are not considered to represent industries for this purpose. in a particular economic sector, such as the utilities, hospital and healthcare facilities, or industrial development sectors. The views and interpretations by the Fund stated in this paragraph may change due to changes in the law or interpretations of the law, including laws pertaining to municipal obligations and the taxability of interest paid on those obligations, and due to other factors.

The following investment limitations are not fundamental and may be changed without shareholder approval as to the Fund:

(ii) The Fund may borrow money only (a) from a bank (as defined in Section 2(a)(5) of the 1940 Act) or (b) by engaging in reverse repurchase agreements to the extent such agreements may be deemed to be a borrowing under the 1940 Act. The Fund will not purchase any security while borrowings representing more than 5% of its total assets are outstanding.

(iii) The Fund does not currently intend to purchase any security if, as a result, more than 15% of its net assets would be invested in investments that are deemed to be illiquid because they are subject to legal or contractual restrictions on resale or because they cannot be sold or disposed of in the ordinary course of business at approximately the prices at which they are valued.

Thornburg Investment Trust has adopted the following fundamental investment policies applicable to the Short Duration Municipal Fund which may not be changed unless approved by a majority of the Fund’s outstanding voting securities. The Fund may not:

(1) Invest in securities other than municipal obligations (including participations therein) and temporary investments within the percentage limitations stated in the Prospectus;

(4) Underwrite any issue of securities (except to the extent that the Fund may be deemed to be an underwriter within the meaning of the 1933 Act in the disposition of restricted securities);

(5) Purchase or sell real estate unless acquired as a result or ownership of securities or other instruments (but this shall not prevent the Fund from investing in securities or other instruments backed by real estate or securities of companies engaged in the real estate business, nor shall it prevent the Fund from holding real estate as a result of the Fund’s efforts to restructure a bond or other loan obligation that was secured by real estate);

(6) Purchase or sell physical commodities unless acquired as a result of ownership of securities or other instruments (but this shall not prevent the Fund from purchasing or selling options, futures contracts, or from investing in securities or other instruments backed by physical commodities);

(7) Lend any security or make any other loan if, as a result, more than 33 1/3% of its total assets would be lent to other parties, but this limitation does not apply to lending of portfolio securities, purchases of debt obligations or other instruments, or to repurchase agreements;

(8) With respect to 75% of the Fund’s total assets, purchase the securities of any issuer (other than securities issued or guaranteed by the U.S. government or any of its agencies or instrumentalities) if, as a result, (a) more than 5% of the Fund’s total assets would be invested in the securities of that issuer, or (b) the Fund would hold more than 10% of the outstanding voting securities of that issuer; or

For purposes of the restriction stated in paragraph (1), above, “municipal obligations” are also deemed to include investments in investment companies (such as exchange traded funds and closed end funds) which invest substantially all of their assets in municipal obligations, and other direct and indirect investments in municipal obligations which produce income that the Fund is permitted under the Internal Revenue Code to treat as excludable from gross income for purposes of determining its exempt interest dividends under the Code. Also for purposes of the restriction stated in paragraph (1), above, the Fund’s temporary investments may include investments of a portion or all of the Fund’s daily cash balances in Thornburg Capital Management Fund or in any other investment company within the same “group of investment companies” (as defined in Section 12(d)(1)(G) of the 1940 Act); provided that any such investments will comply with Section 12(d)(1)(G) of the 1940 Act and rules thereunder.

In connection with restriction stated in paragraph (3), above, the 1940 Act currently permits an investment company to borrow money if the borrowings do not exceed one-third of the company’s total assets after subtracting liabilities other than the borrowings.

The Fund’s limitation on investing more than 25% of the Fund’s total assets in the same industry, as described in paragraph (9) above, also applies to investments in the same group of industries. In determining whether an issuer should be classified in a particular industry or industry group for purposes of that limitation, Thornburg may rely on its own analysis of the issuer or on available third party industry classifications. The limitation on investing in industries and industry groups does not apply to an investment by the Fund in a particular economic sector, such as the utilities, hospital and healthcare facilities, or industrial development sectors. Additionally, for purposes of applying the limitation described in paragraph (9) above, issuers of the following securities will not be considered to be members of any industry: securities of the U.S. Government and its agencies and instrumentalities; municipal obligations the income from which is exempt from the regular federal income tax; and repurchase agreements collateralized by such obligations. Notwithstanding the foregoing, to the extent that the income from a municipal obligation is derived principally from the assets and revenues of non-governmental users, the obligation will be deemed to have been issued from the industry of that non-governmental user. The views and interpretations by the Fund stated in this paragraph may change due to changes in the law or interpretations of the law, including laws pertaining to municipal obligations and the taxability of interest paid on those obligations, and due to other factors. The views and interpretations by the Fund stated in this paragraph may change due to changes in the law or interpretations of the law, including laws pertaining to municipal obligations and the taxability of interest paid on those obligations, and due to other factors.

The following investment limitations are not fundamental and may be changed without shareholder approval:

(iv) The Fund does not currently intend to purchase any security if, as a result, more than 15% of its net assets would be invested in securities that are considered by Thornburg to be illiquid because they are subject to legal or contractual restrictions on resale or because they cannot be sold or disposed of in the ordinary course of business at approximately the prices at which they are valued.

Thornburg Investment Trust has adopted the following fundamental investment policies applicable to each of Limited Term Municipal Fund and Limited Term California Fund which may not be changed by either Fund unless approved by a majority of the outstanding shares of that Fund. Neither Fund may:

(1) Invest in securities other than municipal obligations (including participations therein) and temporary investments within the percentage limitations specified in the Prospectus;

(3) Borrow money, except for temporary or emergency purposes and not for investment purposes, and then only in an amount not exceeding 5% of the value of the Fund’s total assets at the time of borrowing;

(4) Pledge, mortgage or hypothecate its assets, except to secure borrowings permitted by subparagraph (3) above;

(5) Issue senior securities as defined in the 1940 Act, except insofar as the Fund may be deemed to have issued a senior security by reason of (a) entering into any repurchase agreement; (b) purchasing any securities on a when-issued or delayed delivery basis; or (c) borrowing money in accordance with the restrictions described above;

(6) Underwrite any issue of securities, except to the extent that, in connection with the disposition of portfolio securities, it may be deemed to be an underwriter under the federal securities laws;

(7) Purchase or sell real estate and real estate mortgage loans, but this shall not prevent the Fund from investing in municipal obligations secured by real estate or interests therein;

(8) Purchase or sell commodities or commodity futures contracts or oil, gas or other mineral exploration or development programs;

(9) Make loans, other than by entering into repurchase agreements and through the purchase of municipal obligations or temporary investments in accordance with its investment objective, policies and limitations;

(10) Make short sales of securities or purchase any securities on margin, except for such short-term credits as are necessary for the clearance of transactions;

(11) Write or purchase puts, calls, straddles, spreads or other combinations thereof, except to the extent that securities subject to a demand obligation or to a remarketing agreement may be purchased as set forth in the Prospectus or this Statement of Additional Information;

(12) Invest more than 5% of its total assets in securities of unseasoned issuers which, together with their predecessors, have been in operation for less than three years excluding (i) obligations of, or guaranteed by, the United States government, its agencies, instrumentalities and authorities and (ii) obligations secured by the pledge of the faith, credit and taxing power of any entity authorized to issue municipal obligations;

(13) Invest more than 5% of its total assets in securities which the Fund is restricted from selling to the public without registration under the 1933 Act;

(14) Purchase securities of any issuer if such purchase at the time thereof would cause more than 10% of the voting securities of any such issuer to be held by the Fund;

(15) Purchase securities of other investment companies, except in connection with a merger, consolidation, reorganization or acquisition of assets;

(16) Purchase securities (other than securities of the United States government, its agencies, instrumentalities and authorities) if, as a result, more than 25% of the Fund’s total assets would be invested in any one industry; or

(17) Purchase or retain the securities of any issuer other than the securities of the Fund if, to the Fund’s knowledge, those officers and directors of the Fund, or those officers and directors of Thornburg, who individually own beneficially more than 1/2 of 1% of the outstanding securities of such issuer, together own beneficially more than 5% of such outstanding securities.

For the purpose of applying the limitations set forth in paragraphs (2) and (12) above, an issuer shall be deemed a separate issuer when its assets and revenues are separate from other governmental entities and its securities are backed only by its assets and revenues. Similarly, in the case of a nongovernmental user, such as an industrial corporation or a privately owned or operated hospital, if the security is backed only by the assets and revenues of the nongovernmental user, then such nongovernmental user would be deemed to be the sole issuer. Where a security is also guaranteed by the enforceable obligation of another entity it shall also be included in the computation of securities owned that are issued by such other entity. In addition, for purposes of paragraph (2) above, a remarketing party entering into a remarketing agreement with a Fund as described in the Prospectus or this Statement of Additional Information shall not be deemed an “issuer” of a security or a “guarantor” of a Municipal Lease subject to that agreement.

For the purposes of applying the limitation set forth in paragraph (7) above, a Fund is permitted to hold real estate if doing so is the result of the Fund’s efforts to restructure a bond or other loan obligation that was secured by real estate.

For the purposes of applying the limitation set forth in paragraph (10) above, any initial and variation margin payments that a Fund may be required to make in connection with its permitted investment strategies do not constitute the purchase of securities “on margin.”

Each Fund’s limitation on investing more than 25% of the Fund’s total assets in the same industry, as described in paragraph (16) above, also applies to investments in the same group of industries. In determining whether an issuer should be classified in a particular industry or industry group for purposes of that limitation, Thornburg may rely on its own analysis of the issuer or on available third party industry classifications. The limitation on investing in industries and industry groups does not apply to an investment by the Fund in a particular economic sector, such as the utilities, hospital and healthcare facilities, or industrial development sectors. Additionally, for purposes of applying the limitation described in paragraph (16) above, issuers of the following securities will not be considered to be members of any industry: securities of the U.S. Government and its agencies and instrumentalities; municipal obligations the income from which is exempt from the regular federal income tax; and repurchase agreements collateralized by such obligations. Notwithstanding the foregoing, to the extent that the income from a municipal obligation is derived principally from the assets and revenues of non-governmental users, the obligation will be deemed to have been issued from the industry of that non-governmental user. The views and interpretations by the Fund stated in this paragraph may change due to changes in the law or interpretations of the law, including laws pertaining to municipal obligations and the taxability of interest paid on those obligations, and due to other factors.

With respect to temporary investments, in addition to the foregoing limitations, a Fund will not enter into a repurchase agreement if, as a result thereof, more than 5% of its net assets would be subject to repurchase agreements.

Although each of these Funds has the right to pledge, mortgage or hypothecate its assets in order to comply with certain state statutes on investment restrictions, a Fund will not, as a matter of operating policy (which policy may be changed by the board of Trustees without shareholder approval), pledge, mortgage or hypothecate its portfolio securities to the extent that at any time the percentage of pledged securities will exceed 10% of its total assets.

In addition, neither of these Funds will purchase the securities of any issuer if as a result more than 15% of the value of the Fund’s net assets would be invested in restricted securities, unmarketable securities and other illiquid investments (including repurchase agreements of more than seven days maturity and other securities which are not readily marketable).

In the event the Limited Term Municipal Fund or the Limited Term California Fund acquires disposable assets as a result of the exercise of a security interest relating to municipal obligations, the Fund will dispose of such assets as promptly as possible.

Intermediate New Mexico Fund, Intermediate New York Fund and Intermediate Municipal Fund

Thornburg Investment Trust has adopted the following fundamental investment policies respecting Intermediate New Mexico Fund, Intermediate New York Fund and Intermediate Municipal Fund, which may not be changed as to any of these Funds unless approved by a majority of the outstanding shares of the Fund. Unless otherwise specified below as applicable to only one of the Funds, none of Intermediate New Mexico Fund, Intermediate New York Fund and Intermediate Municipal Fund may:

(1) Invest in securities other than municipal obligations (including participations therein) and temporary investments within the percentage limitations specified in the Prospectus;

(2) The Intermediate Municipal Fund may not purchase any security if, as a result, more than 5% of its total assets would be invested in securities of any one issuer, excluding obligations of, or guaranteed by, the United States government, its agencies, instrumentalities and authorities. Any of the single state Intermediate Funds may invest more than 5% of its portfolio assets in the securities of a single issuer provided that it may not purchase any security (other than securities issued or guaranteed as to principal or interest by the United States or its instrumentalities) if, as a result, more than 5% of the Trust’s total assets would be invested in securities of a single issuer;

(4) Pledge, mortgage or hypothecate its assets, except to secure borrowings permitted by subparagraph (3) above;

(6) Underwrite any issue of securities, except to the extent that, in connection with the disposition of portfolio securities, it may be deemed to be an underwriter under the federal securities laws;

(7) Purchase or sell real estate and real estate mortgage loans, but this shall not prevent the Funds from investing in municipal obligations secured by real estate or interests therein;

(8) Purchase or sell commodities or commodity futures contracts or oil, gas or other mineral exploration or development programs;

(10) Make short sales of securities or purchase any securities on margin, except for such short-term credits as are necessary for the clearance of transactions;

(13) Invest more than 5% of its total assets in securities which the Fund is restricted from selling to the public without registration under the 1933 Act;

(14) Purchase securities of any issuer if such purchase at the time thereof would cause more than 10% of the voting securities of any such issuer to be held by the Fund;

(15) Purchase securities of other investment companies, except in connection with a merger, consolidation, reorganization or acquisition of assets;

(17) Purchase or retain the securities of any issuer other than the securities issued by the Fund itself if, to the Fund’s knowledge, those officers and trustees of the Fund, or those officers and directors of Thornburg, who individually own beneficially more than 1/2 of 1% of the outstanding securities of such issuer, together own beneficially more than 5% of such outstanding securities; or

(18) Purchase the securities of any issuer if as a result more than 10% of the value of the Fund’s net assets would be invested in restricted securities, unmarketable securities and other illiquid investments (including repurchase agreements of more than seven days maturity and other securities which are not readily marketable).

For the purposes of applying the limitations set forth in paragraphs (2) and (12) above, an issuer shall be deemed a separate issuer when its assets and revenues are separate from other governmental entities and its securities are backed only by its assets and revenues. Similarly, in the case of a nongovernmental user, such as an industrial corporation or a privately owned or operated hospital, if the security is backed only by the assets and revenues of the nongovernmental user, then the nongovernmental user would be deemed to be the sole issuer. Where a security is also guaranteed by the enforceable obligation of another entity it shall also be included in the computation of securities owned that are issued by such other entity. In addition, for purposes of paragraph (2) above, a remarketing party entering into a remarketing agreement with a Fund as described in the Prospectus or in this Statement of Additional Information shall not be deemed an “issuer” of a security or a “guarantor” pursuant to the agreement.

With respect to temporary investments, in addition to the foregoing limitations a Fund will not enter into a repurchase agreement if, as a result thereof, more than 5% of its net assets would be subject to repurchase agreements.

Although each Fund has the right to pledge, mortgage or hypothecate its assets, each Fund will not, as a matter of operating policy (which policy may be changed by its Trustees without shareholder approval), pledge, mortgage or hypothecate its portfolio securities to the extent that at any time the percentage of pledged securities will exceed 10% of its total assets.

In the event a Fund acquires disposable assets as a result of the exercise of a security interest relating to municipal obligations, it will dispose of such assets as promptly as possible.

Thornburg Investment Trust has adopted the following fundamental investment policies applicable to Strategic Municipal Income Fund which may not be changed unless approved by a majority of the Fund’s outstanding voting securities. Strategic Municipal Income Fund may not:

(1) Invest in securities other than municipal obligations (including participations therein) and temporary investments within the percentage limitations stated in the Prospectus;

(4) Underwrite any issue of securities (except to the extent that the Fund may be deemed to be an underwriter within the meaning of the 1933 Act in the disposition of restricted securities);

For purposes of the restriction stated in paragraph (1), above, “municipal obligations” are also deemed to include investments in investment companies (such as exchange traded funds and closed end funds) which invest substantially all of their assets in municipal obligations, and other direct and indirect investments in municipal obligations which produce income that the Fund is permitted under the Internal Revenue Code to treat as excludable from gross income for purposes of determining its exempt interest dividends under the Code. Also for purposes of the restriction stated in number 1, above, the Fund’s temporary investments may include investments of a portion or all of the Fund’s daily cash balances in Thornburg Capital Management Fund or in any other investment company within the same “group of investment companies” (as defined in Section 12(d)(1)(G) of the 1940 Act); provided that any such investments will comply with Section 12(d)(1)(G) of the 1940 Act and rules thereunder

The following investment limitations are not fundamental and may be changed without shareholder approval:

Each Fund will from time to time display performance information, including yield, dividend returns, total return, and average annual total return, in advertising, sales literature, and reports to shareholders. Yield is computed by dividing the Fund’s net interest and dividend income for a given 30 days or one month period by the maximum share offering price at the end of the period. The result is “annualized” to arrive at an annual percentage rate. In addition, the Fund may use the same method for 90 day or quarterly periods. Total return is the change in share value over time, assuming reinvestment of any dividends and capital gains. “Cumulative total return” describes total return over a stated period, while “average annual total return” is a hypothetical rate of return which, if achieved annually, would have produced the same cumulative total return if performance had been constant for the period shown. Average annual return tends to reduce variations in return over the period, and investors should recognize that the average figures are not the same as actual annual returns. A Fund may display return information for differing periods without annualizing the results and without taking sales charges into effect.

All performance figures are calculated separately for each class of shares of a Fund. The figures are historical, and do not predict future returns. Actual performance will depend upon the specific investments held by a Fund, and upon the Fund’s expenses for the period.

Yield quotations include a standardized calculation which computes yield for a 30-day or one month period by dividing net investment income per share during the period by the maximum offering price on the last day of the period. The standardized calculation will include the effect of semiannual compounding and will reflect amortization of premiums for those bonds which have a market value in excess of par. New schedules based on market value will be computed each month for amortizing premiums. With respect to mortgage-backed securities or other receivables-backed obligations, the Fund will amortize the discount or premium on the outstanding principal balance, based upon the cost of the security, over the remaining term of the security. Gains or losses attributable to actual monthly paydowns on mortgage-backed obligations will be reflected as increases or decreases to interest income during the period when such gains or losses are realized. Provided that any such quotation is also accompanied by the standardized calculation referred to above, a Fund may also quote non-standardized performance data for a specified period by dividing the net investment income per share for that period by either the Fund’s average public offering price per share for that same period or the offering price per share on the first or last day of the period, and multiplying the result by 365 divided by the number of days in the specified period. For purposes of this non-standardized calculation, net investment income will include accrued interest income plus or minus any amortized purchase discount or premium less all accrued expenses. The primary differences between the results obtained using the standardized performance measure and any non-standardized performance measure will be caused by the following factors: (1) The non-standardized calculation may cover periods other than the 30-day or one month period required by the standardized calculation; (2) The non-standardized calculation may reflect amortization of premium based upon historical cost rather than market value; (3) The non-standardized calculation may reflect the average offering price per share for the period or the beginning offering price per share for the period, whereas the standardized calculation always will reflect the maximum offering price per share on the last day of the period; (4) The non-standardized calculation may reflect an offering price per share other than the maximum offering price, provided that any time the Fund’s return is quoted in reports, sales literature or advertisements using a public offering price which is less than the Fund’s maximum public offering price, the return computed by using the Fund’s maximum public offering price also will be quoted in the same piece; (5) The non-standardized return quotation may include the effective return obtained by compounding the monthly dividends.

For the Funds’ investments denominated in foreign currencies, income and expenses are calculated first in their respective currencies, and are then converted to U.S. dollars, either when they are actually converted or at the end of the 30-day or one month period, whichever is earlier. Capital gains and losses generally are excluded from the calculation as are gains and losses from currency exchange rate fluctuations.

Income calculated for the purposes of calculating the Funds’ yields differs from income as determined for other accounting purposes. Because of the different accounting methods used, and because of the compounding of income assumed in yield calculations, a Fund’s yield may not equal its distribution rate, the income paid to a shareholder’s account, or the income reported in the Fund’s financial statements.

Yield information may be useful in reviewing a Fund’s performance and in providing a basis for comparison with other investment alternatives. However, each Fund’s yield fluctuates, unlike investments that pay a fixed interest rate over a stated period of time. When comparing investment alternatives, investors should also note the quality and maturity of the portfolio securities of respective investment companies they have chosen to consider.

Total returns quoted in advertising reflect all aspects of a Fund’s return, including the effect of reinvesting dividends and capital gain distributions, and any change in the Fund’s net asset value (“NAV”) over a stated period. Average annual total returns are calculated by determining the growth or decline in value of a hypothetical historical investment in a Fund over a stated period, and then calculating the annually compounded percentage rate that would have produced the same result if the rate of growth or decline in value had been constant over the period. For example, a cumulative total return of 100% over ten years would produce an average annual return of 7.18%, which is the steady annual rate of return that would equal 100% growth on a compounded basis in ten years. While average annual returns are a convenient means of comparing investment alternatives, investors should realize that a Fund’s performance is not constant over time, but changes from year to year, and the average annual returns represent averaged figures as opposed to the actual year-to-year performance of the Fund. In addition to average annual total returns, a Fund may quote unaveraged or cumulative total returns reflecting the simple change in value an investment over a stated period. Average annual and cumulative total returns may be quoted as a percentage or as a dollar amount, and may be calculated for a single investment, a series of investments, or a series of redemptions, over any time period. Total returns may be broken down into their components of income and capital (including capital gains and changes to share price) in order to illustrate the relationship of these factors and their contributions to total return. Total returns may be quoted on a before-tax or after-tax basis and may be quoted with or without taking a Fund’s maximum sales charge into account. Excluding a Fund’s sales charge from a total return calculation produces a higher total return figure. Total returns, yields, and other performance information may be quoted numerically or in a table, graph, or similar illustration.

A Municipal Fund, Limited Term U.S. Government Fund, Ultra Short Income Fund, Limited Term Income Fund, Core Plus Bond Fund, or Strategic Income Fund also may illustrate performance or the characteristics of its investment portfolio through graphs, tabular data or other displays which describe (i) the average portfolio maturity or average duration of the Fund’s portfolio securities relative to the maturities or durations of other investments, (ii) the relationship of yield and maturity of the Fund to the yield and maturity of other investments (either as a comparison or through use of standard bench marks or indices such as the Treasury yield curve), (iii) changes in the Fund’s share price or net asset value in some cases relative to changes in the value of other investments, and (iv) the relationship over time of changes in the Fund’s (or other investments’) net asset value or price and the Fund’s (or other investments’) investment return.

Charts and graphs using the Fund’s net asset values, adjusted net asset values, and benchmark indices may be used to exhibit performance. An adjusted NAV includes any distributions paid by the Fund and reflects all elements of its return. Unless otherwise indicated, the Fund’s adjusted NAVs are not adjusted for sales charges, if any.

The Funds may illustrate performance using moving averages. A long-term moving average is the average of each week’s adjusted closing NAV or total return for a specified period. A short-term moving average NAV is the average of each day’s adjusted closing NAV for a specified period. Moving average activity indicators combine adjusted closing NAVs from the last business day of each week with moving averages for a specified period the produce indicators showing when an NAV has crossed, stayed above, or stayed below its moving average.

Each Fund’s performance may be compared to the performance of other mutual funds in general, or to the performance of particular types of mutual funds. These comparisons may be expressed as mutual fund ranking prepared by Lipper Analytical Services, Inc. (“Lipper”), an independent service that monitors the performance of mutual funds. Lipper generally ranks funds on the basis of total return, assuming reinvestment of distributions, but does not take sales charges or redemption fees into consideration, and is prepared without regard to tax consequences. In addition to the mutual fund rankings the Fund’s performance may be compared to stock, bond, and money market mutual fund performance indices prepared by Lipper or other organizations. When comparing these indices, it is important to remember the risk and return characteristics of each type of investment. For example, while stock mutual funds may offer higher potential returns, they also carry the highest degree of share price volatility. Likewise, money market funds may offer greater stability of principal, but generally do not offer the higher potential returns from stock mutual funds. From time to time, the Fund’s performance may also be compared to other mutual funds tracked by financial or business publications and periodicals. For example, the Fund may quote Morningstar, Inc. in its advertising materials. Morningstar, Inc. is a mutual fund rating service that rates mutual funds on the basis of risk-adjusted performance. Rankings that compare the performance of Thornburg Funds to one another in appropriate categories over specific periods of time may also be quoted in advertising. Performance rankings and ratings reported periodically in financial publications also may be used. These performance analyses ordinarily do not take sales charges into consideration and are prepared without regard to tax consequences.

Each Fund may be compared in advertising to Certificates of Deposit (“CDs”) or other investments issued by banks or other depository institutions. Mutual funds differ from bank investments in several respects. For example, while a Fund may offer greater liquidity or higher potential returns than CDs, a Fund does not guarantee a shareholder’s principal or return, and Fund shares are not FDIC insured.

Thornburg may provide information designed to help individuals understand their investment goals and explore various financial strategies. Such information may include information about current economic and political conditions; materials that describe general principles of investing, such as asset allocation, diversification, risk tolerance, and goal setting; questionnaires designed to help create a personal financial profile; worksheets used to project savings needs bases on assumed rates of inflation and hypothetical rates of return; and action plans offering investment alternatives. Materials may also include discussions of other Thornburg mutual funds.

Ibbotson Associates, a wholly owned subsidiary of Morningstar, Inc. (“Ibbotson”), provides historical returns of the capital markets in the United States, including common stocks, small capitalization stocks, long-term corporate bonds, intermediate-term government bonds, long-term government bonds, Treasury bills, the U.S. rate of inflation (based on the CPI), and combinations of various capital markets. The performance of these capital markets is based on the returns of differed indices.

The Funds may use the performance of these capital markets in order to demonstrate general risk-versus-reward investment scenarios. Performance comparisons may also include the value of a hypothetical investment in any of these capital markets. The risks associated with the security types in the capital market may or may not correspond directly to those of a Fund. A Fund may also compare performance to that of other compilations or indices that may be developed and made available in the future, and advertising, sales literature and shareholder reports also may discuss aspects of periodic investment plans, dollar cost averaging and other techniques for investing to pay for education, retirement and other goals. In addition, a Fund may quote or reprint financial or business publications and periodicals, including model portfolios or allocations, as they relate to current economic and political conditions, fund management, portfolio composition, investment philosophy, investment techniques and the desirability of owning a particular mutual fund. A Fund may present its fund number and CUSIP number, and discuss or quote its current portfolio manager.

The Funds may quote various measures of volatility and benchmark correlation in advertising. In addition, the Funds may compare these measures to those of other funds. Measures of volatility seek to compare a Fund’s historical share price fluctuations or total returns to those of a benchmark. Measures of benchmark correlation indicate how valid a comparative benchmark may be. All measures of volatility and correlation are calculated using averages of historical data. In advertising, a Fund may also discuss or illustrate examples of interest rate sensitivity.

Momentum indicators show a Fund’s price movements over specific periods of time. Each point on the momentum indicator represents the Fund’s percentage change in price movements over that period. A Fund may advertise examples of the effects of periodic investment plans, including the principle of dollar cost averaging. In such a program, an investor invests a fixed dollar amount in a fund at periodic intervals, thereby purchasing fewer shares when prices are high and more shares when prices are low. While such a strategy does not assure a profit or guard against loss in a declining market, the investor’s average cost per share can be lower than if fixed numbers of shares are purchased at the same intervals. In evaluating such a plan, investors should consider their ability to continue purchasing shares during periods of low price levels. The Funds may be available for purchase through retirement plans or other programs offering deferral of, or exemption from, income taxes, which may produce superior after-tax returns over time. For example, a $1,000 investment earning a taxable return of 10% annually would have an after-tax value of $1,949 after ten years, assuming tax was deducted from the return each year at a 31% rate. An equivalent tax-deferred investment would have an after-tax value of $2,100 after ten years, assuming tax was deducted at a 31% rate from the tax-deferred earnings at the end of the ten-year period.

The benchmark indices described in the Prospectus are products of third party index providers. Data respecting those benchmark indices are the property of those third party providers and have been licensed for use by the Funds. The Funds accept no liability for any errors or omissions relating to the benchmark index data, and the third party providers accept no liability for the use of those data by the Funds. The following additional disclaimers relate to certain of the benchmark indices.

Source ICE Data Indices, LLC (“ICE DATA”), is used with permission. ICE DATA, ITS AFFILIATES AND THEIR RESPECTIVE THIRD PARTY SUPPLIERS DISCLAIM ANY AND ALL WARRANTIES AND REPRESENTATIONS, EXPRESS AND/OR IMPLIED, INCLUDING ANY WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR USE, INCLUDING THE INDICES, INDEX DATAANDANYDATAINCLUDED IN, RELATED TO, OR DERIVED THEREFROM. NEITHER ICE DATA, ITS AFFILIATES NOR THEIR RESPECTIVE THIRD PARTY PROVIDERS SHALL BE SUBJECT TO ANY DAMAGES OR LIABILITY WITH RESPECT TO THE ADEQUACY, ACCURACY, TIMELINESS OR COMPLETENESS OF THE INDICES OR THE INDEX DATA OR ANY COMPONENT THEREOF, AND THE INDICES AND INDEX DATA AND ALL COMPONENTS THEREOF ARE PROVIDED ON AN “AS IS” BASIS AND YOUR USE IS AT YOUR

OWN RISK. ICE DATA, ITS AFFILIATES AND THEIR RESPECTIVE THIRD PARTY SUPPLIERS DO NOT SPONSOR, ENDORSE, OR RECOMMEND THORNBURG INVESTMENT TRUST OR ANY OF ITS PRODUCTS OR SERVICES.

Source: MSCI. The MSCI information may only be used for your internal use, may not be reproduced or redisseminated in any form and may not be used as a basis for or a component of any financial instruments or products or indices. None of the MSCI information is intended to constitute investment advice or a recommendation to make (or refrain from making) any kind of investment decision and may not be relied on as such. Historical data and analysis should not be taken as an indication or guarantee of any future performance analysis, forecast or prediction. The MSCI information is provided on an “as is” basis and the user of this information assumes the entire risk of any use made of this information. MSCI, each of its affiliates and each other person involved in or related to compiling, computing or creating any MSCI information (collectively, the “MSCI Parties”) expressly disclaims all warranties (including, without limitation, any warranties of originality, accuracy, completeness, timeliness, non-infringement, merchantability and fitness for a particular purpose) with respect to this information. Without limiting any of the foregoing, in no event shall any MSCI Party have any liability for any direct, indirect, special, incidental, punitive, consequential (including, without limitation, lost profits) or any other damages. (www.msci.com)

The following discussion summarizes certain federal tax considerations generally affecting the Funds and shareholders. Certain state tax consequences associated with investments in the Municipal Funds are also summarized below. This discussion does not provide a detailed explanation of all tax consequences, and shareholders are advised to consult their own tax advisors with respect to the particular federal, state, local and foreign tax consequences to them of an investment in the Funds. In particular, this discussion addresses aspects of investment by persons who are not individuals only in a very limited manner.

This discussion is based on the Internal Revenue Code of 1986, as amended (the “Code”), Treasury Regulations issued thereunder, the laws of certain specified states (respecting the Municipal Funds) and judicial and administrative authorities as in effect on the date of this Statement of Additional Information, all of which are subject to changes, which changes may be retroactive.

Each Fund has elected and intends to qualify for treatment as a regulated investment company under Subchapter M of the Code. In each taxable year when a Fund qualifies for treatment as a regulated investment company, it will not be subject to federal income tax on net investment income and net capital gains which are timely distributed to its shareholders.

If in any year a Fund fails to qualify for the treatment afforded by Subchapter M of the Code, the Fund would be taxed as a corporation on its income. Distributions to the shareholders would be treated as ordinary income to the extent of the Fund’s earnings and profits, and would be treated as nontaxable returns of capital to the extent of the shareholders’ respective bases in their shares. Further distributions would be treated as amounts received on a sale or exchange or property. In any year a Fund qualifies as a regulated investment company but fails to distribute all of its net investment income and net capital gains, the Fund is subject to taxes on the undistributed portion of its net income and capital gains. Although each Fund intends to distribute all of its net income currently and any capital gains annually, it could have undistributed net income if, for example, expenses of the Fund were reduced or disallowed on audit.

Each shareholder will be notified annually by their Fund as to the amount and characterization of distributions paid to or reinvested by the shareholder for the preceding taxable year. The Fund may be required to withhold federal income tax from distributions otherwise payable to a shareholder if (i) the shareholder has failed to furnish the Fund with his taxpayer identification number, (ii) the Fund is notified that the shareholder’s number is incorrect, (iii) the Internal Revenue Service notifies the Fund that the shareholder has failed properly to report certain income, or (iv) when required to do so, the shareholder fails to certify under penalty of perjury that he is not subject to this withholding. The backup withholding tax rate on distributions is currently 28%.

Certain shareholders specified in the Code are exempt from the backup withholding noted in the preceding paragraph. A Fund may be required to obtain certain information from a shareholder to identify that shareholder’s status as a person exempt from backup withholding. Persons exempt from the backup withholding noted in the preceding paragraph may under certain circumstances still be subject to other types of federal income tax withholding. Shareholders should consult their tax advisors for more information.

Distributions of investment company taxable income (including net short-term capital gains) are taxable to shareholders as ordinary income. Certain exempt interest dividends are exempt from federal and certain states’ income taxes, as described below under “Municipal Funds - Income Dividends.” Distributions of investment company taxable income may be eligible for the corporate dividends-received deduction to the extent attributable to a Fund’s dividend income from U.S. corporations, and if other applicable requirements are met. However, the alternative minimum tax applicable to corporations may reduce the benefit of the dividends-received deduction. Distributions of net capital gains (the excess of net long-term capital gains over net short-term capital losses) designated by a Fund as capital gain dividends are not eligible for the dividends-received deduction and will generally be taxable to shareholders as long-term capital gains, regardless of the length of time the Fund’s shares have been held by a shareholder. Generally, dividends and distributions are taxable to shareholders, whether received in cash or reinvested in shares of a Fund. Any distributions that are not from a Fund’s investment company taxable income or net capital gain may be characterized as a return of capital to shareholders or, in some cases, as capital gain. Shareholders will be notified annually as to the federal tax status of dividends and distributions they receive and any tax withheld thereon.

A person seeking to invest in shares of a Fund through a taxable account should consider a Fund’s unrealized gains and losses, and any capital loss carryforwards, which are disclosed in the annual and semiannual reports to shareholders issued by the Fund. Embedded, unrealized gains, if realized by the Fund upon a sale or other disposition of the investments to which the gains relate, and not offset by realized losses, result in capital gains distributions to all shareholders, including persons who just purchased Fund shares, which may be subject to income tax. Unrealized losses, if realized by the Fund through sales of investments, and capital loss

carryforwards from previously realized losses, may offset gains realized by the Fund on sales of appreciated investments, so offsetting the capital gains distributions that otherwise would be made to shareholders.

Pursuant to the American Taxpayer Relief Act of 2012, the maximum federal tax rate for individual taxpayers on long-term capital gains from sales of securities and on certain qualifying dividends on corporate stock issued by domestic corporations and certain “qualified foreign corporations” is 20%. Qualified foreign corporations are corporations incorporated in a U.S. possession, corporations whose stock is readily tradable on an established securities market in the U.S. and corporations eligible for the benefits of a comprehensive income tax treaty with the United States and which satisfy certain other requirements. Foreign personal holding companies, foreign investment companies and passive foreign investment companies are not treated as qualified foreign corporations. These rates do not apply to corporate taxpayers. Each Fund will separately designate distributions of any qualifying long-term capital gains or qualifying dividends earned by the Fund. A shareholder must also satisfy a 60-day holding period requirement with respect to any distributions of qualifying dividends in order to obtain the benefit of the lower tax rates imposed on those distributions. Distributions attributable to a Fund’s income from bonds and other debt obligations, dividends from most foreign companies, and distributions by real estate investment trusts or regulated investment companies will not generally qualify for the lower rates. Some hedging activities may cause a dividend that would otherwise be subject to the lower tax rate applicable to a qualifying dividend to be taxed at the rate of tax applicable to ordinary income.

A Fund’s investments in certain derivatives, foreign currency transactions, options, futures contracts, hedging transactions, forward contracts, investments in passive foreign investment companies, and certain other transactions will be subject to special tax rules, the effect of which may be to accelerate income to the Fund, defer Fund losses, convert capital gain into taxable ordinary income or convert short-term capital losses into long-term capital losses. Engaging in swap transactions also may result in distributions of taxable income or gain to shareholders, and also may cause a Fund to currently recognize income with respect to payments to be received in the future. Certain Fund transactions, including investments in derivative instruments, transactions in foreign currencies or foreign currency-denominated instruments, and hedging activities may produce differences between the Fund’s book and taxable income, and distributions by the Fund may consequently be treated in some instances as returns of capital.

A Fund’s distributions of realized capital gains may be reduced if the Fund has capital loss carryforwards available. A Fund’s net capital losses are not deductible against the Fund’s net investment income.

Distributions by a Fund result in a reduction in the net asset value of the Fund’s shares. Should distributions reduce the net asset value below a shareholder’s cost basis, the distribution would nevertheless be taxable to the shareholder as ordinary income or capital gain as described above, even though, from an investment standpoint, it may constitute a partial return of capital. In particular, investors should consider the tax implications of buying shares just prior to a distribution. The price of shares purchased at that time includes the amount of the forthcoming distribution. Persons purchasing just prior to a distribution will then receive a partial return of capital upon the distribution, which will nevertheless be taxable to them.

A 3.8% Medicare contribution tax is imposed on the “net investment income” of individuals, estates, and trusts whose income exceeds certain threshold amounts. Net investment income generally includes for this purpose distributions of income dividends and capital gains paid by the Funds and otherwise includible in adjusted gross income, and capital gains recognized on the sale, redemption or exchange of Fund shares. Shareholders are advised to consult their tax advisors regarding the possible implications of this additional tax on their investment in a Fund.

The Municipal Funds each intend to satisfy conditions (including requirements as to the proportion of its assets invested in municipal obligations) which will enable each Fund to designate distributions from the interest income generated by its investments in municipal obligations, which are exempt from federal income tax when received by the Fund, as Exempt Interest Dividends. Shareholders receiving Exempt Interest Dividends will not be subject to federal income tax on the amount of those dividends, except to the extent the alternative minimum tax may apply. Although the interest received from municipal securities generally is exempt from federal income tax, a Municipal Fund may invest a portion of its total assets in municipal securities subject to the federal alternative minimum tax. Accordingly, investment in a Municipal Fund could cause noncorporate shareholders to be subject to (or result in an increased liability under) the federal alternative minimum tax. If this is the case, the Municipal Fund’s net after-tax return to you may be lower. A Municipal Fund would be unable to designate Exempt Interest Dividends if, at the close of any quarter of its taxable year, more than 50% of the value of the Fund’s total assets consists of assets other than municipal obligations. Additionally, if in any year the Fund qualified as a regulated investment company but failed to distribute all of its net income, the Fund would be taxable on the undistributed portion of its net income. Although each Fund intends to distribute all of its net income currently, it could have undistributed net income if, for example, expenses of the Fund were reduced or disallowed on audit.

Distributions by each Municipal Fund of net interest income received from certain temporary investments (such as certificates of deposit, commercial paper and obligations of the United States government, its agencies, instrumentalities and authorities), net short-term capital gains realized by the Fund, if any, and realized amounts attributable to market discount on bonds, will be taxable to shareholders for federal income tax purposes as ordinary income whether received in cash or additional shares. Distributions of any net long-term capital gains by a Municipal Fund will be taxable for federal income tax purposes as long-term capital gains, except that gains attributable to market discount on portfolio investments are characterized as ordinary income. Distributions to shareholders will not qualify for the dividends received deduction for corporations.

The exemption from federal income tax for distributions of interest income from municipal obligations which are designated Exempt Interest Dividends will not necessarily result in exemption under the income or other tax laws of any state or local taxing authority.

The exemption from the State of California personal income taxes for distributions of interest income in the Limited Term California Fund applies only to shareholders who are residents of the State of California, and only to the extent such income qualifies as “exempt-interest dividends” under Section 17145 of the California Revenue and Taxation Code and is not derived from interest on obligations from any state other than from California or its political subdivisions.

Distributions by Intermediate New Mexico Fund attributable to interest on obligations of the State of New Mexico and its political subdivisions and their agencies (and interest on obligations of certain United States territories and possessions) will not be

subject to individual income taxes imposed by the State of New Mexico. Capital gains distributions will be subject to the New Mexico personal income tax.

Distributions by Intermediate New York Fund attributable to interest on obligations of the State of New York, its agencies and political subdivisions (and interest on obligations of certain United States territories and possessions) is excluded in determining the New York adjusted gross income of individuals residing in New York. These distributions are similarly excludable by individuals residing in New York City for purposes of computing the New York City income tax.

Distributions may be subject to different treatment under the laws of the different states and local taxing authorities. Shareholders should consult their own tax advisors in this regard.

The foregoing is a general and abbreviated summary of selected provisions of the Code and Treasury Regulations presently in effect as they directly govern the taxation of distributions of income dividends by the Municipal Funds, and this summary primarily addresses tax consequences to individual shareholders. For complete provisions, reference should be made to the pertinent Code sections and Treasury Regulations. The Code and Treasury Regulations are subject to change by legislative or administrative action, and any such change may be retroactive with respect to Fund transactions. Shareholders are advised to consult their own tax advisors for more detailed information concerning the federal taxation of the Funds and the income tax consequences to their shareholders.

The Funds’ counsel, April, Dolan & Koehler, P.C., has not made and normally will not make any review of the proceedings relating to the issuance of the municipal obligations or the basis for any opinions issued in connection therewith. In the case of certain municipal obligations, federal tax exemption is dependent upon the issuer (and other users) complying with certain ongoing requirements. There can be no assurance that the issuer (and other users) will comply with these requirements, in which event the interest on such municipal obligations could be determined to be taxable, in most cases retroactively from the date of issuance.

Under the Code, gains or losses attributable to fluctuations in foreign currency exchange rates which occur between the time a Fund accrues income or other receivable or accrues expenses or other liabilities denominated in a foreign currency and the time a Fund actually collects such receivable or pays such liabilities generally are treated as ordinary income or ordinary loss. Similarly, on disposition of debt obligations denominated in a foreign currency and on disposition of certain financial contracts and options, gains or losses attributable to fluctuations in the value of foreign currency between the date of acquisition of the security or contract and the date of disposition also are treated as ordinary gain or loss. These gains and losses, referred to under the Code as “Section 988” gains and losses, may increase or decrease the amount of a Fund’s net investment income to be distributed to its shareholders as ordinary income.

Income received by a Fund from sources within foreign countries may be subject to withholding and other income or similar taxes imposed by such countries. If more than 50% of the value of a Fund’s total assets at the close of its taxable year consists of securities of foreign corporations, that Fund will be eligible and may elect to “pass through” to the Fund’s shareholders the amount of foreign income and similar taxes paid by that Fund. Pursuant to this election, a shareholder will be required to include in gross income (in addition to taxable dividends actually received) his pro rata share of the foreign taxes paid by a Fund, and will be entitled either to deduct (as an itemized deduction) his pro rata share of foreign income and similar taxes in computing his taxable income or to use it as a foreign tax credit against his U.S. federal income tax liability, subject to limitations. No deduction for foreign taxes may be claimed by a shareholder who does not itemize deductions, but such a shareholder may be eligible to claim the foreign tax credit (see below). Each shareholder will be notified within 60 days after the close of the relevant Fund’s taxable year whether the foreign taxes paid by the Fund will “pass through” for that year. Furthermore, the amount of the foreign tax credit that is available may be limited to the extent that dividends from a foreign corporation qualify for the lower tax rate on “qualifying dividends.”

Generally, a credit for foreign taxes is subject to the limitations that it may not exceed the shareholder’s U.S. tax attributable to his foreign source taxable income. For this purpose, if the pass-through election is made, the source of a Fund’s income flows through to its shareholders. With respect to a Fund, gains from the sale of securities will be treated as derived from U.S. sources and certain currency fluctuations gains, including fluctuation gains from foreign currency denominated debt obligations, receivables and payables, will be treated as ordinary income derived from U.S. sources. The limitation on the foreign tax credit is applied separately to foreign source passive income (as defined for purposes of the foreign tax credit), including the foreign source passive income passed through by a Fund. Shareholders may be unable to claim a credit for the full amount of their proportionate share of the foreign taxes paid by a Fund. The foreign tax credit limitation rules do not apply to certain electing individual taxpayers who have limited creditable foreign taxes and no foreign source income other than passive investment-type income. The foreign tax credit is eliminated with respect to foreign taxes withheld on dividends if the dividend-paying shares or the shares of the Fund are not held by the Fund or the shareholders, as the case may be, for periods specified in the Code. If a Fund is not eligible to make the election to “pass through” to its shareholders its foreign taxes, the foreign income taxes it pays generally will reduce investment company taxable income and the distributions by a Fund will be treated as United States source income.

If a Fund engages in short selling of securities, the gain or loss on the short sale is generally recognized when the Fund closes the short sale by delivering the borrowed securities to the lender, rather than when the borrowed securities are sold. Short sales may increase the net short-term capital gains realized by a Fund, which would be taxable as ordinary income when distributed to the Fund’s shareholders.

Upon the sale or exchange of his shares, a shareholder realizes a taxable gain or loss depending upon his basis in the shares. The gain or loss will be treated as capital gain or loss if the shares are capital assets in the shareholder’s hands, which generally may be eligible for reduced federal tax rates, depending on the shareholder’s holding period for the shares. Any loss realized on a sale or exchange will be disallowed to the extent that the shares disposed of are replaced (including replacement through the reinvestment of dividends and capital gain distributions in a Fund) within a period of 61 days beginning 30 days before and ending 30 days after the disposition of the shares. In such a case, the basis of the shares acquired will be adjusted to reflect the disallowed loss. Any loss realized by a shareholder on the sale of a Fund’s shares held by the shareholder for six months or less will be treated for federal income tax

purposes as a long-term capital loss to the extent of any distributions of capital gains dividends received by the shareholder with respect to such shares.

In some cases, shareholders will not be permitted to take sales charges into account for purposes of determining the amount of gain or loss realized on the disposition of their shares. This prohibition generally applies where (1) the shareholder incurs a sales charge in acquiring the shares of a regulated investment company, (2) the shares are disposed of before the ⁹1st day after the date on which they were acquired, and (3) the shareholder subsequently acquires shares of the same or another regulated investment company and the otherwise applicable sales charge is reduced or eliminated under a “reinvestment right” received upon the initial purchase of the shares. In that case, the gain or loss recognized will be determined by excluding from the tax basis of the shares exchanged all or a portion of the sales charge incurred in acquiring those shares. This exclusion applies to the extent that the otherwise applicable sales charge with respect to the newly acquired shares is reduced as a result of having incurred a sales charge initially. Sales charges affected by this rule are treated as if they were incurred with respect to the shares acquired under the reinvestment. This provision may be applied to successive acquisitions of shares.

The laws of the several states and local taxing authorities vary with respect to the taxation of distributions, and shareholders of each Fund are advised to consult their own tax advisors in that regard. In particular, investors who are not individuals are advised that the preceding discussion relates primarily to tax consequences affecting individuals, and the tax consequences of an investment by a person which is not an individual may be very different. Each Fund will advise shareholders within 60 days of the end of each calendar year as to the percentage of income derived from each state in which the Fund has any municipal obligations in order to assist shareholders in the preparation of their state and local tax returns.

The Foreign Account Tax Compliance Act (“FATCA”) generally requires a Fund to obtain information sufficient to identify the status of each of its shareholders under FATCA, as described more fully below. If a shareholder fails to provide this information or otherwise fails to comply with FATCA, a Fund may be required to withhold under FATCA at a rate of 30% with respect to that shareholder, depending on the type of payment and shareholder account, on certain payments made from the Fund, including distributions characterized by the Fund as capital gain dividends and the proceeds of the sale, redemption or exchange of Fund shares. If a payment by a Fund is subject to FATCA withholding, the Fund or its agent is required to withhold even if such payment would otherwise be exempt from withholding.

Payments to a Fund shareholder will generally not be subject to FATCA withholding, provided the shareholder provides the Fund with such certifications, waivers or other documentation or information as the Fund requires, including, to the extent required, documentation or information respecting such shareholder’s direct and indirect owners, to establish the shareholder’s FATCA status and otherwise to comply with these rules. In order to avoid withholding, a shareholder that is a “foreign financial institution” (“FFI”) must either (i) become a “participating FFI” by entering into a valid U.S. tax compliance agreement with the IRS, (ii) qualify for an exception from the requirement to enter into such an agreement, for example by becoming a “deemed compliant FFI,” or (iii) be covered by an applicable intergovernmental agreement between the United States and a non-U.S. government to implement FATCA. In any of these cases, the investing FFI generally will be required to provide a Fund with appropriate identifiers, certifications or documentation concerning its status.

A Fund will disclose the information that it receives from (or concerning) its shareholders to the IRS, non-U.S. taxing authorities or other parties as necessary to comply with FATCA, related intergovernmental agreements or other applicable law or regulation.

Each investor and prospective investor is urged to consult its tax adviser regarding the applicability of FATCA and any other reporting requirements with respect to the investor’s own situation.

When an investor or the investor’s financial intermediary makes an initial investment in shares of a Fund, the Fund’s transfer agent will open an account on the books of the Fund, and the investor or financial intermediary will receive a confirmation of the opening of the account. Thereafter, whenever a transaction, other than the reinvestment of interest income, takes place in the account - such as a purchase of additional shares or redemption of shares or a withdrawal of shares represented by certificates - the investor or the financial intermediary will receive a confirmation statement giving complete details of the transaction. Shareholders also will receive at least quarterly statements setting forth all distributions of income and other transactions in the account during the period and the balance of full and fractional shares. The final statement for the year will provide information for income tax purposes.

Any distributions of investment income, net of expenses, and the annual distributions of net realized capital gains, if any, will be credited to the accounts of shareholders in full and fractional shares of the Fund at net asset value on the payment or distribution date, as the case may be. Upon written notice to the Fund’s transfer agent, a shareholder may elect to receive periodic distributions of net investment income in cash. Such an election will remain in effect until changed by written notice to the transfer agent, which change may be made at any time in the sole discretion of the shareholder.

INVESTMENT ADVISOR, INVESTMENT ADVISORY AGREEMENTS, & ADMINISTRATIVE SERVICES AGREEMENTS

Pursuant to an Investment Advisory Agreement in respect of each Fund, Thornburg Investment Management, Inc. (“Thornburg” or the “advisor”), 2300 North Ridgetop Road, Santa Fe, New Mexico 87506, acts as investment advisor for, and will manage the investment and reinvestment of the assets of, each of the Funds in accordance with the Funds’ respective investment objectives and policies, subject to the general supervision and control of the Trustees of Thornburg Investment Trust.

Thornburg is paid a fee by each Fund, in the percentage amounts set forth in the Prospectus.

The fee paid by each Fund is allocated among the different classes of shares offered by the Fund based upon the average daily net assets of each class of shares. All fees and expenses are accrued daily and deducted before payment of dividends. In addition to the fees of Thornburg, each Fund will pay all other costs and expenses of its operations. Each Fund also will bear the expenses of registering and qualifying the Fund and its shares for distribution under federal and state securities laws, including legal fees.

The Trust’s Trustees (including a majority of the Trustees who are not “interested persons” within the meaning of the 1940 Act) have approved the Investment Advisory Agreement applicable to each of the Funds, and annually consider the renewal of the agreement applicable to each of the Funds. In connection with their general supervision of Thornburg, and as an important element of their annual consideration of a renewal of the Investment Advisory Agreement applicable to each Fund, the Trustees receive and consider reports from Thornburg throughout the year. These reports address a wide variety of topics, including particularly Thornburg’s services to each Fund and its selection of investments of pursuit of each Fund’s investment objectives.

The Trustees have considered the responsibilities of mutual fund trustees generally and the Trustees’ understandings of shareholders’ expectations about the management of the mutual funds in which they have invested. The Trustees have concluded, based upon these discussions and a consideration of applicable law, that the principal obligation of mutual fund trustees is to assess the nature and quality of an investment advisor’s services, and to confirm that the advisor actively and competently pursues the mutual fund’s objectives. The Trustees have further concluded that while mutual fund trustees should determine that a fund’s fees and costs are reasonable in relation to the services rendered and generally in line with those charged by other investment advisors, putting an investment advisory agreement “out to bid” as a matter of course would be inconsistent with shareholder interests and contrary to shareholder expectations when they invested in a fund, and that mutual fund trustees should not do so unless an advisor materially failed to pursue a fund’s objectives in accordance with its policies or for other equally important reasons. The Trustees also observed in their deliberations that Thornburg Fund shareholders appear to invest with a long-term perspective, and that in reviewing the Funds’ performance, the Trustees should focus on the longer-term perspective rather than current fashions or short-term performance.

The Trust’s Trustees most recently determined to renew the Investment Advisory Agreement applicable to each Fund on September 19, 2023.

In anticipation of their recent consideration of the Investment Advisory Agreement’s renewal, the independent Trustees met in May 2023 to consider aspects of their annual evaluation of the advisor’s service to all of the Funds, to plan the annual evaluation of the advisor’s performance and to discuss preliminarily the information the advisor would present to the Trustees for their review. The independent Trustees met in a second independent session in July 2023 to further define certain portions of the information to be submitted by the advisor. The independent Trustees met again in a September 2023 independent session with a mutual fund analyst firm retained by the independent Trustees to provide explanations of comparative cost and expense information, comparative investment performance information and other data obtained and analyzed by the consulting firm, and in their independent session discussed their evaluations of the Funds’ fee and expense levels, investment performance and other information presented for each Fund. The independent Trustees also conferred independently with legal counsel respecting the factors typically considered in evaluating renewal of an advisory agreement, and conferred in a separate portion of their session with representatives of management to receive explanations of certain aspects of the information they had requested. Representatives of the advisor subsequently reviewed portions of the information with the Trustees and addressed questions from the Trustees at a full meeting session of the Trustees scheduled later in September for that purpose, and the independent Trustees thereafter met in independent session to consider the advisor’s presentations and various specific issues respecting their consideration of the advisory agreement’s renewal. Following these sessions, the Trustees met to consider renewal of the agreement, and the independent Trustees voted unanimously at that meeting to renew the agreement for an additional term of one year.

A discussion regarding the basis for the approval of each Fund’s Investment Advisory Agreement by the Trustees for the period ending October 31, 2024 is contained in the Fund’s Annual Report to Shareholders for the year ended September 30, 2023.

The Investment Advisory Agreement applicable to each Fund may be terminated by either party, at any time without penalty, upon 60 days’ written notice, and will terminate automatically in the event of its assignment. Termination will not affect the right of Thornburg to receive payments on any unpaid balance of the compensation earned prior to termination. The Agreement further provides that in the absence of willful misfeasance, bad faith or gross negligence on the part of Thornburg, or of reckless disregard of its obligations and duties under the Agreement, Thornburg will not be liable for any action or failure to act in accordance with its duties thereunder.

For the three most recent fiscal years with respect to each Fund, Thornburg was entitled to receive the following amounts from each Fund pursuant to the Investment Advisory Agreement applicable to the Fund.

No information is shown for the past three fiscal years for the Core Plus Bond Fund because investment operations for the Fund commenced as of October 2, 2023.

For some or all of the three most recent fiscal years, Thornburg has waived its rights to certain fees which it was otherwise entitled to receive from certain Funds pursuant to the Investment Advisory Agreement applicable to those Funds. The specific amounts waived by Thornburg are as follows:

Thornburg may (but is not obligated to) waive its rights to any portion of its fees in the future, and may use any portion of its fees for purposes of shareholder and administrative services and distribution of Fund shares.

Garrett Thornburg, Chairman and Trustee of Thornburg Investment Trust, is also a director and controlling shareholder of Thornburg, and Brian McMahon, Vice Chairman and Trustee of Thornburg Investment Trust, is also a director of Thornburg. In addition, various individuals who are officers of the Trust also serve as officers of Thornburg, as described below under the caption “Management.”

Thornburg is authorized by the Trust to vote proxies respecting voting securities held by the Funds. In those cases, Thornburg votes proxies in accordance with written Proxy Voting Policies and Procedures (the “Policy”) adopted by Thornburg. The Policy states that the objective of voting a security is to enhance the value of the security, or to reduce potential for a decline in the security’s value. The Policy prescribes procedures for assembling voting information and applying the informed expertise and judgment of Thornburg on a timely basis in pursuit of this voting objective.

The Policy also prescribes a procedure for voting proxies when a vote presents a conflict between the interests of the Fund and Thornburg. If the vote relates to the election of a director in an uncontested election or ratification or selection of independent accountants, the investment advisor will vote the proxy in accordance with the recommendation of any proxy voting service engaged by Thornburg. If no such recommendation is available, or if the vote involves other matters, Thornburg will refer the vote to the Trust’s operations risk oversight committee for direction on the vote or consent to vote on Thornburg’s recommendation.

The Policy authorizes Thornburg to utilize various sources of information in considering votes, including the engagement of service providers who provide analysis and information on the subjects of votes and who may recommend voting positions. Thornburg has engaged Institutional Shareholder Services (“ISS”) to provide these services to Thornburg in connection with voting proxies for each of the Funds. With respect to the Better World International Fund, Thornburg has directed ISS to make voting recommendations using ISS’s Sustainability Proxy Voting Guidelines. ISS states that the Sustainability Proxy Voting Guidelines focus on long term economic value preservation and enhancement through promotion of corporate governance best practices, and represent an approach to corporate governance and proxy voting that aligns with the perspectives of mainstream investors who wish to incorporate environmental, social and governance (“ESG”) considerations into their investment decision-making process to a greater extent. Thornburg may or may not accept recommendations from ISS. Thornburg also may decline to vote in various situations, including cases where an issue is not relevant to the Policy’s voting objective or where it is not possible to ascertain what effect a vote may have on the value of an investment. Thornburg may not be able to vote proxies in cases where proxy voting materials are not delivered to Thornburg in sufficient time for evaluation and voting.

Information regarding how proxies were voted is available on or before August 31 of each year for the twelve months ending the preceding June 30. This information is available (i) without charge, upon request by calling the Advisor toll-free at 1-800-847-0200, (ii) on the Thornburg website at www.thornburg.com, and (iii) on the Securities and Exchange Commission’s website at www.sec.gov.

provision of non-distribution services to the Funds; supervision and direction of and assistance in the preparation of registration statements and other governmental filings, income and other tax returns, and reports and other communications to shareholders; coordination and supervision of certain portfolio valuation functions; monitoring, supervision and conduct of legal compliance functions; providing personnel necessary to furnish the services required by the Administrative Services Agreements together with the office space and other support necessary for those services; and such other services and activities as the parties may agree from time to time.

The Trust pays Thornburg a fee for the services that Thornburg provides pursuant to the Administrative Services Agreements. That fee is computed as an annual percentage of the aggregate average daily net assets of all share classes of all Funds described in this Statement of Additional Information, paid monthly, as follows:

For the three most recent fiscal years with respect to each Fund, the amounts paid to Thornburg by each Fund under the Administrative Services Agreements were as follows:

No information is shown for the past three fiscal years for the Core Plus Bond Fund because investment operations for the Fund commenced as of October 2, 2023.

The agreements applicable to each class may be terminated by either party, at any time without penalty, upon 60 days’ written notice, and will terminate automatically upon assignment. Termination will not affect the service provider’s right to receive fees earned before termination. The agreements further provide that in the absence of willful misfeasance, bad faith or gross negligence on the part of the service provider, or reckless disregard of its duties thereunder, the provider will not be liable for any action or failure to act in accordance with its duties thereunder.

Effective December 28, 2023, the Trust’s principal underwriter, Thornburg Securities Corporation (“TSC”), was reorganized as a new limited liability company known as Thornburg Securities LLC (“TSL”). That reorganization did not constitute an assignment of the Trust’s distribution agreement with Thornburg Securities Corporation because the reorganization did not result in a change in the actual control or management of the underwriter. Following the reorganization, all payments that the Funds are authorized to make to Thornburg Securities Corporation pursuant to the Service Plan and Distribution Plan (as defined below) are made instead to TSL.

Each of the Funds has adopted a plan of distribution pursuant to Rule 12b-1 under the 1940 Act (“Service Plan”), which is applicable to Class A shares and, if offered by that Fund, Class B, Class C, Class C2, Class D and Class I shares. The Service Plan authorizes each Fund to pay to TSL, or to such persons as TSL may direct, out of the assets of the Fund, an annual amount not exceeding 0.25% of the Fund’s average annual assets (not exceeding 0.20% in the case of Class A and Class I shares of Short Duration Municipal Fund and Ultra Short Income Fund), together with any applicable gross receipts tax, sales tax, value added tax, compensating tax or similar exaction imposed by any federal, state or local government, though the aggregate of those taxes shall not exceed 10%. Each Fund has also entered into a distribution agreement with TSL, pursuant to which TSL agrees to provide or obtain from other persons the services described in the Service Plan, and the Fund agrees to pay TSL or other persons as TSL directs for providing or obtaining those services.

TSL, or by other persons at the request or direction of the Trust or TSL, in connection with the provision of services to the shareholders of the Fund pursuant to selling agreements with TSL or other service agreements or similar arrangements with TSL, Thornburg or the Trust, which services include providing personal services to shareholders and maintaining shareholder accounts, including, but not limited to, administrative, transactional, distribution and redemption, and accounting and reporting services with respect to Fund shareholders and accounts, and providing information to shareholders and responding to shareholder inquiries; and (c) such other services and activities as may from time to time be agreed upon by Trustees of the Trust and TSL. Payments by the Fund pursuant to the Service Plan and the related distribution agreement with TSL shall be in addition to any payments made outside of the Service Plan, as authorized by the Trustees of the Trust as not being primarily intended to result in the sale of Fund shares.

In the two most recent fiscal years, the principal type of activity for which payments were made by the Funds under the Service Plan was compensation to securities broker-dealers, financial institutions and other organizations which render services to the applicable class of shareholders, including distribution, shareholder account services, and administrative services. Reimbursements for expenditures incurred by TSL or by other persons at the request or direction of the Trust or TSL for the printing and distribution of reports and prospectuses for use by potential investors in the Funds, preparing and distributing sales literature, providing advertising and engaging in other promotional activities, and other services were de minimis relative to payments made to broker-dealers, financial institutions and other organizations under the Service Plan. The Service Plan does not provide for accrued but unpaid reimbursements for such expenditures to be carried over and reimbursed in later years. TSL has no current intention to request or receive any payment under the Service Plan in respect of a Fund’s Class I shares.

Each Fund offering Class C shares, Class C2 Shares or Class D shares has adopted a plan of distribution pursuant to Rule 12b-1 under the 1940 Act, applicable only to the Class C or Class C2 or, if applicable, Class D shares of that Fund (“Distribution Plan”). The Distribution Plan authorizes each Fund to pay to TSL, or to such persons as TSL may direct, out of the assets of each share class of the Fund to which the Distribution Plan is applicable, an annual amount of: up to 0.75% of the average daily net assets attributable to Class C shares of Core Plus Bond Fund, Strategic Income Fund and each of the Equity Funds; up to 0.40% of the net assets attributable to Class C2 shares of Limited Term Municipal Fund, Intermediate Municipal Fund, Limited Term California Fund, Limited Term U.S. Government Fund and Limited Term Income Fund, up to 0.35% of the average daily net assets attributable to Class C shares of each of Intermediate Municipal Fund and Strategic Municipal Income Fund; and up to 0.25% of the net assets attributable to Class C shares of Limited Term Municipal Fund, Limited Term California Fund, Limited Term U.S. Government Fund and Limited Term Income Fund and Class D shares of Intermediate New Mexico Fund, together with any applicable gross receipts tax, sales tax, value added tax, compensating tax or similar exaction imposed by any federal, state or local government, though the aggregate of those taxes shall not exceed 10%. Each Fund has also entered into a distribution agreement with TSL, pursuant to which TSL agrees to provide or obtain from other persons the services described in the Distribution Plan, and the Fund agrees to pay TSL or other persons as TSL directs for providing or obtaining those services.

Payments by a Fund under the Distribution Plan and the related distribution agreement with TSL may be made for: (a) compensation and ongoing commissions (including incentive compensation) to securities dealers, financial institutions and other organizations which render distribution and administrative services in connection with the distribution of the share classes of the Funds; (b) the printing and distribution of reports and prospectuses for the use of potential investors; (c) preparing and distributing sales literature; (d) providing advertising and engaging in other promotional activities, including direct mail solicitation, and television, radio newspaper and other media advertisements; and (e) such other services and activities as may from time to time be agreed upon by Trustees of the Trust and TSL. The Trust and TSL are authorized under the Distribution Plan to instruct the Funds’ transfer agent or other agents of the Funds to pay these amounts directly to financial services firms or other persons engaged to provide the foregoing services.

For each Fund, the following table shows amounts paid by the Fund in each of the last two fiscal years pursuant to the Service Plan adopted by the Fund.

No information is shown for the past two fiscal years for the Core Plus Bond Fund because investment operations for the Fund commenced as of October 2, 2023.

For each Fund that offers Class C, Class C2 or D shares, the following table shows amounts paid by the Fund in each of the last two fiscal years pursuant to the Distribution Plan adopted by the Fund.

No information is shown for the past two fiscal years for the Core Plus Bond Fund because investment operations for the Fund commenced as of October 2, 2023.

Financial advisors and financial intermediaries who sell shares and hold shares for investors (“intermediaries”) charge compensation in connection with the sale of Fund shares and the servicing of shareholder accounts. Intermediaries receiving this compensation may include securities brokers and dealers, registered investment advisors, banks, trust companies, insurance companies, employee benefit plan and retirement plan administrators, and other institutions that have entered into arrangements with Thornburg or TSL under which they are paid compensation for the sale of Fund shares or the servicing of accounts for their customers. Intermediaries may categorize and disclose these payments to their customers and to members of the public differently than the disclosures in the Prospectus and this SAI.

Thornburg or TSL may pay compensation charged by intermediaries out of amounts that Thornburg or TSL receive from the Funds. Examples of such payments include, but are not limited to: (i) share sales commissions and ongoing asset-based compensation paid by Thornburg or TSL out of sales charges received or expected to be received from the Funds; (ii) amounts paid out of the Rule 12b-1 service and distribution fees that TSL receive from the Funds; and (iii) amounts paid by the Funds to compensate intermediaries who perform services, including subaccounting and subtransfer agency services, that would otherwise need to be provided by the Funds’ transfer agent or other persons hired directly by the Funds.

To the extent permitted by applicable law, including applicable rules promulgated by the Securities and Exchange Commission and the Financial Industry Regulatory Authority (“FINRA”), Thornburg or TSL may also compensate intermediaries out of Thornburg’s or TSL’s own resources. This compensation may be in the form of commissions, finder’s fees or similar cash incentives, “revenue sharing,” and marketing and advertising support. An intermediary may receive this compensation in addition to the Rule 12b-1 or other compensation that the intermediary receives out of the assets of the Funds. This compensation from Thornburg or TSL may provide an incentive to financial intermediaries to actively market the sale of shares of the Funds or to support the marketing efforts of Thornburg or TSL. Examples of the types of services which an intermediary may provide (or may arrange to have a third party provide) in exchange for receiving this compensation from Thornburg or TSL include, but are not limited to: Fund due diligence and business planning assistance; marketing programs and support; operations and systems support; and training for the intermediary’s personnel respecting the Funds and the financial needs of Fund shareholders. Each of Thornburg or TSL may also make payments out of its own resources to compensate an intermediary for costs associated with the intermediary’s marketing efforts (including the cost of attendance at training and educational conferences), and for costs associated with the intermediary’s shareholder support and account maintenance services for its customers or transaction processing (including the payment of certain ticket charges).

During the fiscal year which ended September 30, 2023, Thornburg or TSL (as TSC) paid amounts from its own resources to the following member firms of FINRA, or to the affiliates of such firms, pursuant to written agreements with such firms:

Each of Thornburg and TSL may also make payments out of its own resources to institutions that are not member firms of FINRA and that are not included among, or affiliated with, the institutions listed above.

All orders for the purchase or sale of portfolio securities are placed on behalf of each of the Funds by Thornburg pursuant to its authority under each Fund’s investment advisory agreement. Thornburg also is responsible for the placement of transaction orders for other clients for whom it acts as investment advisor.

Thornburg, in effecting purchases and sales of fixed income securities for the account of each of the Funds, places orders in such a manner as, in the opinion of Thornburg, offers the best available price and most favorable execution of each transaction. Portfolio securities normally will be purchased directly from an underwriter or in the over-the-counter market from the principal dealers in such securities, unless it appears that a better price of execution may be obtained elsewhere. Purchases from underwriters will include a

commission or concession paid by the issuer to the underwriter, and purchases from dealers will include the spread between the bid and asked price.

Similarly, Thornburg places orders for transactions in equity securities in such a manner as, in the opinion of Thornburg, will offer the best available price and most favorable execution of these transactions. In selecting broker dealers, subject to applicable legal requirements, Thornburg considers various relevant factors, including, but not limited to: the size and type of the transaction; the nature and character of the markets for the security to be purchased or sold; the execution efficiency, settlement capability, and financial condition of the broker-dealer firm; the broker-dealer’s execution services rendered on a continuing basis; and the reasonableness of any commissions; and arrangements for payment of Fund expenses. Generally commissions for foreign investments traded will be higher than for U.S. investments and may not be subject to negotiation.

Thornburg may execute a Fund’s portfolio transactions with broker-dealers who provide research and brokerage services to Thornburg. Such services may include, but are not limited to, provision of market information relating to the security, economy, industries or specific companies; order execution systems; technical and quantitative information about the markets; and effecting securities transactions and performing functions incidental thereto (such as clearance and settlement). Research and brokerage services include information and analysis provided electronically through online facilities. The receipt of research from broker-dealers who execute transactions on behalf of the Funds may be useful to Thornburg in rendering investment management services to the Funds.

The receipt of such research may not reduce Thornburg’s normal independent research activities; however, it may enable Thornburg to avoid the additional expenses that could be incurred if Thornburg tried to develop comparable information through its own efforts.

Thornburg may pay, or be deemed to pay, to broker-dealers who provide research and brokerage services to Thornburg, commission rates higher than might otherwise be obtainable from other broker-dealers. Thornburg does not attempt to assign a specific dollar value to the research provided in connection with trades for client accounts or to allocate the relative cost or benefit of research or brokerage services. The research and brokerage services may benefit client accounts other than the specific client account(s) for which a trade is effected, and some or all of the research or brokerage services received with respect to a specific trade may not be used in connection with the account(s) for which the trade was executed. Some of the described services may be available for purchase by Thornburg on a cash basis.

It is Thornburg’s policy, in circumstances where Thornburg receives research or brokerage services from a broker-dealer, to determine in accordance with federal securities laws that: (i) the research or brokerage services are “brokerage or research services” as that term is defined in Section 28(e) of the Securities and Exchange Act of 1934, as amended; (ii) the services provide lawful and appropriate assistance in the performance of Thornburg’s investment management decisions; and (iii) the commissions paid are reasonable in relation to the value of the research or brokerage services provided. In circumstances where Thornburg determines that it has received research or brokerage services that fulfill the requirements under Thornburg’s policy, Thornburg determines the portion of non-qualifying products or services and pays for those products or services from its own resources.

During some or all of the three most recent fiscal years or periods, brokerage commissions were paid by Global Opportunities Fund, International Equity Fund, Better Word International Fund, International Growth Fund, Developing World Fund, Small/Mid Cap Core Fund, Small/Mid Cap Growth Fund, Investment Income Builder Fund, Summit Fund, and Strategic Income Fund. The aggregate commissions paid by each of those Funds during each of the last three fiscal years or periods are as follows:

Increases in brokerage commissions paid by a Fund from year to year are primarily attributable to increases in the number of equity trades placed by the Fund, while decreases in brokerage commissions paid by a Fund from year to year are primarily attributable to decreases in the number of equity trades placed by the Fund. The variance in equity trading activity from year-to-year may reflect a number of factors, including the advisor’s identification of investment opportunities for a Fund, the advisor’s decision to rebalance a Fund’s portfolio in response to actual or anticipated changes in market conditions, equity purchases made in response to shareholder inflows to a Fund, and equity sales made to meet shareholder redemption requests.

Some of the Funds owned during the fiscal year securities issued by certain of their regular broker dealers. Those broker dealers and the aggregate dollar value of each such broker dealer’s securities held by a Fund on September 30, 2023 are shown below:

Thornburg may use research services provided by and place portfolio transactions with brokerage firms that have provided assistance in the distribution of shares of the Funds to the extent permitted by law. Thornburg may use research services provided by and place agency transactions with TSL if the commissions are fair, reasonable, and comparable to commissions charged by non-affiliated, qualified brokerage firms for similar services. Thornburg may allocate brokerage transactions to broker-dealers who have entered into arrangements with Thornburg under which the broker-dealer allocates a portion of the commissions paid by the Fund toward payment of the Fund’s expenses, such as transfer agent fees or custodian fees. The transaction quality must, however, be comparable to those of other qualified broker-dealers.

Thornburg reserves the right to manage other investment companies and investment accounts for other clients which may have investment objectives similar to those of the Funds. Subject to applicable laws and regulations, Thornburg will attempt to allocate equitably portfolio transactions among the Funds and the portfolios of its other clients purchasing securities whenever decisions are made to purchase or sell securities by a Fund and one or more of such other clients simultaneously. In making such allocations the main factors to be considered will be the respective investment objectives of the Fund and the other clients, the size and nature of investment positions then held by the Fund and the other clients, and the strategy, timing and restrictions applicable respectively to the Fund and the other clients. While this procedure could have a detrimental effect on the price or amount of the securities available to a Fund from time to time, it is the opinion of the Funds’ Trustees that the benefits available from Thornburg’s organization will outweigh any disadvantage that may arise from exposure to simultaneous transactions.

The Funds’ respective portfolio turnover rates for the two most recent fiscal years or periods are as follows:

No portfolio turnover figures are provided for the Core Plus Bond Fund because investment operations for the Fund commenced as of October 2, 2023.

Variations in a Fund’s portfolio turnover rate from year-to-year are generally due to repositioning of the Fund’s portfolio in response to changing market conditions.

The Trustees have adopted policies and procedures respecting and limiting the circumstances under which nonpublic holdings information respecting the Funds’ current portfolio holdings information may be disclosed to persons not associated with the Funds, Thornburg, or TSL. “Nonpublic Holdings Information” means any information respecting portfolio investments of any Fund (including but not limited to, the identity of the issuer, number of shares, denominations, purchase or sale dates, countries of origin, maturities or duration, credit ratings, currency in which investments are denominated or corresponding hedging positions, or options, futures or other derivative positions) which has not been made publicly available. The objective in adopting these policies and procedures is to reduce the exposure of the Funds and their shareholders to harm resulting from trading of Fund shares by persons in possession of material nonpublic information respecting the Funds’ portfolio holdings. These policies and procedures are intended to operate in conjunction with Thornburg’s policies prohibiting securities transactions using material nonpublic information. Neither the Funds nor Thornburg nor any affiliate thereof receives compensation or other consideration in connection with the disclosure of information about the Funds’ portfolio holdings.

certain circumstances to: the Trust’s registered independent public accounting firm, independent accounting firms and legal counsel; the Trust’s custodian, subcustodians and securities depositories; valuation and pricing services and agents; financial printing services; mutual fund analysts; securities broker dealers in connection with placing a specific trade in a particular portfolio security; financial consultants to the Funds or investment advisor; certain other specified persons; and persons who are not otherwise specified in the policy in connection with a legitimate business purpose of any Fund and with the approval of the Trust’s chief compliance officer or the chief compliance officer’s designee, the Trustees, or the Trustees’ Governance and Nominating Committee. In any case where nonpublic portfolio holdings information is disclosed to a third party, Thornburg seeks to confirm that the person to whom the disclosure is made is subject to a contractual provision, professional rule or obligation, or undertaking respecting the maintenance of the confidentiality of the nonpublic information. Nonpublic holdings information may also be disclosed to cooperate fully regulatory authorities, subject to laws and regulations respecting disclosure of private or nonpublic information.

As of the date of this Statement of Additional Information, Thornburg has ongoing arrangements that would permit Thornburg to disclose the Funds’ nonpublic portfolio holdings information to the persons noted in the following table. Unless otherwise noted in the table below, there will typically be no lag time between the date of the information and the date on which the information is disclosed.

In addition to the ongoing arrangements described above, the Trust’s policy and procedures respecting disclosure of portfolio holdings information provide for periodic public disclosure of that, as follows:

In any case where it becomes apparent that nonpublic portfolio holdings information has been disclosed other than in accordance with the Trust’s policy and procedures, the trust’s chief compliance officer shall determine appropriate action to be taken, which may include making a corrective public disclosure of the relevant nonpublic information

Portfolio holdings information made publicly available in accordance with this section is no longer nonpublic information subject to the disclosure restrictions in the policies and procedures.

Each of the Funds is a separate “series” or investment portfolios of the Trust. The names of Trustees and officers of the Funds and their principal occupations and affiliations during the past five years are set forth in the table below. Additional information about the particular experiences, qualifications, attributes and skills of each Trustee appears after the table.

Additional Information about the Experiences, Qualifications, Attributes and Skills of Each Trustee

The following disclosure is intended to provide additional information about the particular experiences, qualifications, attributes and skills of each Trustee of the Trust. The Trustees believe that each Trustee is qualified to serve on the board of Trustees in view of (i) the particular experiences, qualifications, attributes and skills of that Trustee, as summarized below and in the table above, and (ii) the actual service and commitment of each Trustee during his or her tenure with the Trust, including the demonstrated ability of each Trustee to exercise effective business judgment in the performance of his or her duties.

Garrett Thornburg, Chairman of Trustees since 1984. Garrett Thornburg is the chairman of Trustees for Thornburg Investment Trust. Mr. Thornburg founded Thornburg Investment Management, Inc. in 1982, Thornburg Securities Corporation in 1984, and Thornburg Investment Trust in 1984. Before forming Thornburg, Mr. Thornburg was a limited partner of Bear Stearns & Co. and a founding member of that firm’s public finance department. He also was chief financial officer of New York State’s Urban Development Corporation, and served as financial advisor to the State of New Mexico’s Board of Finance. He is a member of the Board of Governors of the Investment Company Institute and serves on the Board of Directors of the New Mexico School for the Arts – Art Institute. He is also the President of the Thornburg Foundation, and former recipient of the Philanthropist of the Year award from the Journal Santa Fe. He is a former board member of the National Dance Institute of New Mexico, the Santa Fe Institute and the Santa Fe Community Foundation. Mr. Thornburg received his BA from Williams College and his MBA from Harvard University.

Brian J. McMahon, Trustee since 2001, member of Governance & Nominating Committee and Operations Risk Oversight Committee. Brian McMahon is the vice chairman of Thornburg Investment Trust and a managing director, and the chief investment officer of Thornburg Investment Management, Inc. Joining Thornburg in 1984, Mr. McMahon participated in organizing and managing each Fund of the Trust, served as Thornburg’s president from 1997 until 2016, as its chief executive officer from 2008 until 2016, as its chief; investment officer from 2016 until 2019, and, as chief investment strategist, he currently serves as a key voice for the investment team and Thornburg clients. Before joining Thornburg, Mr. McMahon held various corporate finance positions at Norwest Bank. Mr. McMahon received his BA in Economics and Russian Studies from the University of Virginia and his MBA from the Amos Tuck School at Dartmouth College.

Lisa Black, Trustee since 2023, member of Audit Committee and Operations Risk Oversight Committee. Lisa Black is a retired executive and Chartered Financial Analyst with over 30 years in the investment management industry. Ms. Black brings extensive investment strategy and risk management experience having overseen fixed income assets as well as launching and managing mutual funds at TIAA-CREF and Nuveen, a wholly owned subsidiary of TIAA, one of the world’s largest asset managers. Ms. Black has served on the boards of private and nonprofit organizations, including TIAA Life Company and University Liggett School, and is a current member of the board and chair of the audit & risk committee of Smith College. Ms. Black holds a bachelor’s degree in Economics from Smith College and an MBA from the University of Michigan Ross School of Business.

Sally Corning, Trustee since 2012, member of Audit Committee and Governance & Nominating Committee. Sally Corning is a founding partner of Santa Fe, New Mexico based private equity firm, Sun Mountain Capital. Prior to forming Sun Mountain, Ms. Corning spent 15 years working in private equity and investment banking for Credit Suisse, Morgan Stanley and Dean Witter Reynolds. In addition to sitting on the corporate boards of certain of the private portfolio companies that Sun Mountain Capital has invested in, Ms. Corning has served on the boards of several nonprofit organizations, including the Santa Fe Preparatory School, the Santa Fe Community Foundation, the Santa Fe Mountain Center, and the Westside YMCA in New York City, and is a current member of the board and the finance committee of Excellent Schools New Mexico. Ms. Corning holds a bachelor’s degree in Finance from Georgetown University and an MBA from Columbia University’s Graduate School of Business.

Susan H. Dubin, Trustee since 2004, member of Audit Committee and Operations Risk Oversight Committee. Susan Dubin manages the investments for her extended family. From 1974 to 1996 Ms. Dubin was a vice president of JP Morgan Chase & Co. (formerly Chemical Bank) where she was involved in corporate banking, marketing of financial services to corporate customers, and the delivery of private banking services. Ms. Dubin has served with numerous community and charitable organizations, including the MICDS (Mary Institute and St. Louis Country Day School) in St. Louis, Missouri, the Battery Dance Company in New York City, and the National Dance Institute – New Mexico, Inc. She received her BA from Briarcliff College.

David L. Gardner, Trustee since 2015, Chair of Governance & Nominating Committee and member of Operations Risk Oversight Committee. David Gardner is a retired executive from the global asset management industry, most notably as an original team member of iShares ETFs. Mr. Gardner has over 25 years of experience in the global asset management industry and has worked extensively in the US, Asia and Europe. Prior to joining iShares Mr. Gardner worked for US based asset management firms in distribution management capacities. Mr. Gardner holds a BA in Economics from Eastern Illinois University and a CIMA Certification from Wharton School and Investment Management Consultants Associations.

Patrick J. Talamantes, Trustee since 2019, Chair of Audit Committee. Patrick Talamantes is President of Talamantes Strategies, a management consulting firm. Mr. Talamantes is a former executive from the news and media industry, most recently having served as Chief Executive Officer, and prior to that Chief Financial Officer, of The McClatchy Company, a publicly traded local news organization in various local markets across the U.S. Mr. Talamantes has over 30 years of experience in corporate finance and banking, having served as Chief Financial Officer of Sinclair Broadcast Group, Inc., Treasurer of River City Broadcasting, LP, and Vice President of Chemical Banking Corporation. Mr. Talamantes has board experience through his service on the boards of various McClatchy investees. He has also served as a past chair of the Greater Sacramento Economic Council, a private-public partnership led by area CEOs to develop an advanced economy; and served on the board of Recruitology, an HR technology startup in the recruitment space. In addition, Mr. Talamantes serves on the board of the Breakthrough Collaborative, a non-profit that seeks to improve education equity in 24 cities across the U.S. Mr. Talamantes has also been a director of The Associated Press and the News Media Alliance. Mr. Talamantes received his A.B. in Economics from Stanford University and his MBA from The Wharton School of the University of Pennsylvania.

Owen D. Van Essen, Trustee since 2004, Lead Independent Trustee and member of Governance & Nominating Committee and Operations Risk Oversight Committee. Owen Van Essen is the president of Dirks, Van Essen & April LLC, Santa Fe, New Mexico, which acts as a broker, appraiser and consultant to the newspaper publishing industry. Before joining the firm, he was general manager and business manager of the Worthington Daily Globe, Worthington, Minnesota. Mr. Van Essen has served with numerous community, educational, professional and charitable organizations, including most recently the St. Michaels High School Foundation and the Santa Fe Preparatory School. He received his BA in Business Administration from Dordt College, Iowa.

James W. Weyhrauch, Trustee since 1996, Chair of Operations Risk Oversight Committee and member of Audit Committee. James Weyhrauch is a real estate broker in Santa Fe, New Mexico. Until 2019, he was is the vice chairman of the board of directors, and was from 1997-2000 president and from 2000-2004 chief executive officer, of Nambe LLC, a Santa Fe, New Mexico manufacturer of tabletop and giftware products; and since 2015 has served as General Partner, Investments of Genext LLC, a family investment partnership. Mr. Weyhrauch also has extensive experience with other privately held enterprises, and a background in sales and marketing. He participates in a variety of community and charitable organizations, including the Santa Fe Chamber of Commerce, the Santa Fe Preparatory School and Junior Achievement. Mr. Weyhrauch received his BA in Finance from Southern Methodist University.

The board of Trustees is currently comprised of nine Trustees, two of whom are “interested persons” of the Funds (as the term “interested” is defined in the 1940 Act) and seven of whom are not interested persons of the Funds. Garrett Thornburg currently serves as the chairman of the board of Trustees, and Owen Van Essen currently serves as the lead independent Trustee. The lead independent Trustee is a spokesman for and leader of the independent Trustees, and in that role the lead independent Trustee performs a variety of functions, including: presiding at all sessions of the independent Trustees and, in consultation with legal counsel, preparing the agenda for each session of independent Trustees and coordinating and directing the preparation and delivery of materials and presentations appropriate for each session; in consultation with the Trust’s chairman, president, fund accounting and legal counsel, preparing the draft agenda for each general meeting of Trustees; acting as a liaison between the independent Trustees and senior management of the advisor respecting communications on certain topics; coordinating with and directing legal counsel in the acquisition, preparation and development of information for review and consideration of continuation of contracts with the advisor and affiliates; and performing such other functions as the independent Trustees may request from time to time. The Trustees have also established three standing committees, the Audit Committee, the Governance and Nominating Committee, and the Operations Risk Oversight Committee, each of which is discussed in more detail below under the section entitled “Structure and Responsibilities of the Committees of the Trustees.” The Trustees may form other committees when deemed appropriate.

The Trustees review the leadership structure of the board of Trustees and the performance of the Trustees on an annual basis. The Trustees currently believe that the leadership structure of the board of Trustees is appropriate, in light of the characteristics of the Trust and each of the Funds, to enable the Trustees to oversee the Trust and its service providers. The Trustees have considered the number of Funds in the Trust, and the similarities and differences among the investment objectives and strategies of those Funds, and have determined that the board of Trustees contains a sufficient number of Trustees, and a sufficient percentage of independent Trustees, to discharge the Trustees’ oversight function. The Trustees believe that Mr. Thornburg’s long tenure as a Trustee of the Trust, his ongoing association with the Trust’s advisor and the fact that that association allows Mr. Thornburg to interact routinely with members of the advisor’s staff, and his familiarity with the Trust’s business and affairs and with events impacting the investment management industry more broadly, enable Mr. Thornburg to serve as an effective chairman of the board of Trustees. The Trustees believe that Mr. Van Essen’s long tenure as a Trustee of the Trust, his business and other professional experience, and his familiarity with the Trust’s business and affairs and with events impacting the investment management industry more broadly, enable Mr. Van Essen to serve as an effective lead independent Trustee The Trustees also believe that the scope of each committee’s activities and the composition of each committee is currently appropriate, and that the committee structure allows the Trustees to allocate responsibility for various topics among the board and its committees in a manner which facilitates the oversight of the Trust and its service providers.

The Trustees are responsible for the general supervision of the Funds, including the supervision of Thornburg, which provides day-to-day management of the Funds under the terms of the Investment Advisory Agreement and Administrative Services Agreement. As part of their annual review of the leadership structure of the board of Trustees, described above, the Trustees consider whether the structure of the board and its committees continues to permit the Trustees to effectively exercise their oversight function. In that regard, the Trustees typically consider, among other factors: the number of Trustees and each Trustee’s qualifications, experience and skills; the frequency with which the Trustees and their committees confer with representatives of Thornburg and the Trust’s other service providers; the number of Funds and the ability of the Trustees to devote sufficient time and attention to matters specific to each Fund; the role of the Funds’ chief compliance officer and the opportunity for the Trustees to interact with the chief compliance officer; and the composition of each committee of the Trustees and the scope of the responsibilities delegated to those committees.

The Funds are subject to a number of risks, including investment, compliance, operational and valuation risks. On a day-to-day basis, risk management is the responsibility of Thornburg and the Funds’ other service providers. Risk oversight also comprises part of the Trustees’ general oversight function. The Trustees and their committees seek to monitor risks to the Funds by meeting no less frequently than quarterly (and in practice, more often) with senior officers of the Trust, members of the Funds’ portfolio management teams, the Funds’ chief compliance officer and the Funds’ legal counsel, and by receiving periodic reports from the Funds’ independent registered public accounting firm and other service providers to the Funds. The Trust’s Operations Risk Oversight Committee assists the Trustees in reviewing and evaluating the identification, analysis and management of operations risk by Thornburg and other significant service providers to the Trust. The duties of the Operations Risk Oversight Committee are described in more detail below under the section entitled “Structure and Responsibilities of the Committees of the Trustees.” The Trustees have also adopted various written policies and procedures designed to address particular risks to the Funds, including the detection and prevention of violations of federal securities laws. At least annually, the Trustees receive a report from the Funds’ chief compliance officer respecting the effectiveness of those policies and procedures. Notwithstanding the foregoing, the Trustees acknowledge that it is not possible to identify all of the risks that may affect the Funds or to develop processes and controls to eliminate or mitigate the occurrence or effects of certain risks on the Funds. Furthermore, some risks may simply be beyond the control of the Funds or their service providers. The Trustees may, at any time and in their sole discretion, change the manner in which they supervise risk.

The Trustees have an Audit Committee, which is comprised of five Trustees who are not interested persons, Patrick J. Talamantes (chair), Lisa Black, Sally Corning, Susan H. Dubin, and James W. Weyhrauch. The Audit Committee discharges its duties in accordance with an Audit Committee Charter, which provides that the committee will, among other functions: (i) evaluate the independence, performance and qualifications of the Trust’s independent accountants; (ii) receive and review reports from the independent accountants respecting the planning, scope and staffing of audits of the Funds’ financial statements, the accountants’ independence, the accountants’ internal quality control procedures, all accounting policies and procedures identified by the accountants as critical to the preparation of the Funds’ annual financial statements, all non-audit services provided by the auditors for the Funds, and any material issues in any peer review, governmental investigation, or otherwise respecting any audit conducted by the accountants; (iii) receive and review results of audits of the Funds’ financial statements with the independent accountants, including any deficiencies, uncorrected misstatements, or similar matters identified by the accountants during such an audit, any material alternative accounting treatments that the accountants discussed with the Funds’ management during the audit, and any disagreements between the accountants and management respecting financial reporting matters; (iv) perform the applicable duties imposed on a mutual fund’s governing board by the Investment Company Act of 1940, and by regulations and guidance thereunder, with respect to oversight of portfolio pricing and valuation; (v) receive and review the Funds’ annual audited financial statements and semi-annual unaudited financial statements; (vi) receive and review communications from management, and at least annually from the independent accountants, respecting matters arising in connection with periodic certifications under Form N-CSR; (vii) receive and review complaints from any source regarding accounting, internal accounting controls, financial reporting or disclosure, and audit matters relating to the Trust; (viii) require the Trust’s legal counsel to report to the committee any matter which may have a significant effect on a Fund’s financial statements; (ix) receive and review any report made to the committee in accordance with any compliance policy or procedure subject to the oversight of the committee, and receive and review reports from the chief compliance officer on matters relating to the committee’s responsibilities; (x) receive and review reports from management’s mutual fund administration department to evaluate the functioning of that department; (xi) to the extent the Audit Committee determines that it may be necessary or appropriate to the functions of the committee, receive and review reports from representatives of other significant service providers to the Trust to evaluate the services delivered by those providers; and (xii) such other matters assigned by the Trustees to the committee. The Audit Committee is also responsible for the selection of the independent accountants that audit the Funds’ annual financial statements. The committee held four meetings in the Trust’s fiscal year ended September 30, 2023.

The Trustees have a Governance and Nominating Committee, which is comprised of four Trustees, David Gardner (chair), Brian J. McMahon, Sally Corning, and Owen D. Van Essen. Mr. Gardner, Ms. Corning and Mr. Van Essen are not interested persons. Mr. McMahon is an interested person because he is a director and an officer of the Funds’ investment advisor, but is prohibited from participating in the selection or nomination of individuals to serve as independent Trustees of the Trust. The Governance and Nominating Committee discharges its duties in accordance with a Governance and Nominating Committee Charter, which provides that the committee will: (i) conduct evaluations of the performance of the Trustees and their committees in accordance with the Trust’s Corporate Governance Procedures and Guidelines (the “Governance Procedures”); (ii) select and nominate individuals for election as Trustees of the Trust who are not “interested persons” of the Trust as that term is defined in the 1940 Act; and (iii) perform the additional functions specified in the Governance Procedures and such other functions assigned by the Trustees to the committee from time to time. The committee is authorized to consider for nomination as candidates to serve as Trustees individuals recommended by shareholders in accordance with the Trust’s Procedure for Shareholder Communications to Trustees. In accordance with that Procedure for Shareholder Communications to Trustees, shareholders may recommend candidates to serve as Trustees by sending their recommendations to any one or more of the Trustees by United States. Mail or courier delivery at the address of the Trust’s investment advisor. The committee held two meetings in the Trust’s fiscal year ended September 30, 2023.

The Trustees have an Operations Risk Oversight Committee, which is comprised of six Trustees, James W. Weyhrauch (chair), Lisa Black, Susan H. Dubin, David L. Gardner, Brian J. McMahon, and Owen D. Van Essen. Mr. Weyhrauch, Ms. Black, Ms. Dubin, Mr. Gardner, and Mr. Van Essen are not interested persons. As noted above, Mr. McMahon is an interested person because he is a director and an officer of the Funds’ investment advisor. The Operations Risk Oversight Committee discharges its duties in accordance with an Operations Risk Oversight Committee Charter, which provides that the committee will: (i) receive and review, preliminary to its presentation to the Trustees, the annual report of the Trust’s chief compliance officer respecting the Trust’s compliance policies and procedures; (ii) receive and review reports from Thornburg respecting trade execution and the use of client commissions; (iii) receive and review reports from Thornburg respecting its administration of the investment advisor’s policy on voting proxies; (iv) receive and review reports from Thornburg respecting the Funds’ account service arrangements; (v) receive each report submitted by Thornburg or counsel which is required to be submitted to the committee by a policy or procedure of the Trust or Thornburg; (vi) receive and review reports submitted by the chief compliance officer or counsel with respect to any compliance policy or procedure subject to the oversight of the committee that relates to (A) any revision to such a policy or procedure identified by the chief compliance officer or counsel as potentially material, (B) any violation of such a policy or procedure identified as potentially material, and (C) any error or exception in the administration of such a policy or procedure identified as potentially material; (vii) receive and review reports submitted by Thornburg respecting the Trust’s transfer agent, firms providing shareholder services, custodians, records storage providers, business continuity and disaster recovery contractors, and other significant service providers to evaluate the services delivered by those providers; (viii) receive and review reports submitted by Thornburg respecting computer systems and software, electronic communications systems and other technological systems and developments pertaining to the operations of the Trust; (ix) receive and review any changes to contracts with the providers referenced in the preceding two items which are submitted to the committee for review, to the extent such changes would materially affect the scope of the services that those providers deliver to the Trust; (x) confer with Thornburg respecting liability insurance and fidelity bond coverage for the Trust and the Trustees, at the time of proposed renewals of those policies, and make recommendations respecting coverage to the Trustees; (xi) receive and review reports submitted by Thornburg relating to Thornburg’s committee and staff assigned to risk identification, analysis and management; (xii) receive and review reports submitted by Thornburg relating liquidity, cybersecurity, derivatives transactions, and anti-money laundering compliance; and (xiii) such other matters assigned by the Trustees to the committee. The committee held three meetings in the Trust’s fiscal year ended September 30, 2023.

The officers and Trustees affiliated with Thornburg serve without any compensation from the Trust. Effective January, 1, 2024, the Trust compensates each Trustee who is not an interested person of the Trust at an annual rate of $230,000, payable quarterly. Fifteen percent of each quarterly payment must be invested by the Trustee in one or more of the Funds, as the Trustee selects, and is subject to an undertaking by the Trustee to retain the shares during the Trustee’s tenure. In addition, the Trust compensates each Trustee $20,000 for each meeting of Trustees attended by the Trustee in person, or video conference, or by telephone, provided, however, that the

compensation is $10,000 for each meeting attended by video conference or by telephone in excess of one such meeting or session in any calendar year. General meetings of Trustees on two or more successive days will be considered one meeting for this purpose.

The Trust also compensates each Trustee $7,000 for each session of independent Trustees attended by the Trustee in excess of five sessions in any calendar year. Notwithstanding the preceding sentence, a session of independent Trustees will not be considered separately compensable if held within one day before or after any session of a general meeting of Trustees.

The Trust compensates the lead independent Trustee and the chair of each standing committee an additional annual compensation, payable in quarterly installments. The individual who serves as lead independent Trustee receives an additional annual compensation of $50,000, the chair of the Audit Committee receives an additional annual compensation of $20,000, and the chair of the Governance and Nominating Committee and the chair of the Operations Risk Oversight Committee each receive an additional annual compensation of $15,000.

The Trust compensates each independent Trustee $3,500 for each session with a Trust service provider, except that if the Trustee is required to travel away from home for the session or sessions, the Trust compensates the Trustee $7,000 for each session of one or two days and $3,500 for each additional day on which a session is conducted.

Independent Trustees are not separately compensated for days spent attending continuing education programs, or for time spent traveling to meetings, continuing education programs or sessions with service providers, apart from the compensation stated in the preceding paragraphs.

The Trust reimburses each independent Trustee for travel and certain out-of-pocket expenses incurred by the Trustee in connection with attending meetings, including attendance at any seminar or educational program relating to the Trustee’s service for the Trust. The Trust does not pay retirement or pension benefits.

The Trust paid fees to the Trustees during the fiscal year ended September 30, 2023 as follows:

*Ms. Black became an Advisory Trustee to the Trust effective April 1, 2023 and was elected as an independent Trustee of the Trust effective October 2, 2023.

The following table shows the dollar range of the shares owned beneficially by each Trustee as of December 31, 2023 in each Fund described in this Statement of Additional Information.

The Trust, the investment advisor to the Trust, and the distributor for the advisor and the Trust, each have adopted a code of ethics under Rule 17j-1 of the 1940 Act. Specified personnel of the Trust, investment advisor and distributor, including individuals engaged in investment management activities and others are permitted under the codes of make personal investments in securities, including securities that may be purchased or held by the Funds. Certain investments are prohibited or restricted as to timing, and personnel subject to the codes must report their investment activities to a compliance officer.

Displayed below is additional information about the portfolio managers identified in the Prospectus.

The compensation of each portfolio manager includes an annual salary, annual bonus, and company-wide profit sharing. Each manager currently named in the Prospectus also owns equity shares in the investment advisor, Thornburg. Both the salary and bonus are reviewed approximately annually for comparability with salaries of other portfolio managers in the industry, using survey data obtained from compensation consultants. The annual bonus is subjective. Criteria that are considered in formulating the bonus include, but are not limited to, the following: revenues available to pay compensation of the manager and all other expenses related to supporting the accounts managed by the manager, including the Trust; multiple year historical total return of accounts managed by the manager, including the Trust, relative to market performance and similar investment companies; single year historical total return of accounts managed by the manager, including the Trust, relative to market performance and similar investment companies; the degree of sensitivity of the manager to potential tax liabilities created for account holders in generating returns, relative to overall return. There is no material difference in the method used to calculate the manager’s compensation with respect to the Trust and other accounts managed by the manager, except that certain accounts managed by the manager may have no income or capital gains tax considerations. To the extent that the manager realizes benefits from capital appreciation and dividends paid to shareholders of Thornburg, such benefits accrue from the overall financial performance of Thornburg.

Most investment advisors and their portfolio managers manage investments for multiple clients, including mutual funds, private accounts, and retirement plans. In any case where a portfolio manager manages the investments of two or more accounts, there is a possibility that conflicts of interest could arise between the manager’s management of a Fund’s investments and the manager’s management of other accounts. These conflicts could include:

The Trust’s investment advisor, Thornburg, has informed the Trust that it has considered the likelihood that any material conflicts of interest could arise between a manager’s management of the Funds’ investments and the manager’s management of other accounts. Thornburg has also informed the Trust that it has not identified any such conflicts that may arise, and has concluded that it has implemented policies and procedures to identify and resolve any such conflict if it did arise.

Set out below for each portfolio manager named in the Prospectus is information respecting the accounts managed by the manager. Except as otherwise noted below, the information presented is current as of September 30, 2023. The information includes the Fund or Funds as to which each individual is a portfolio manager. Except as noted below, as of September 30, 2023 the advisory fee for each of the accounts was not based on the investment performance of the account.

*Mr. Burrell and Mr. Salmond each became a portfolio manager of the Better World International Fund on February 1, 2024, and management of that Fund is included in the number of accounts managed; however, total assets for the number of accounts managed shown are as of September 30, 2023.

Displayed below for each of the portfolio managers named in the Prospectus is the dollar range of the individual’s beneficial ownership of shares in the Fund or Funds as to which the individual is a manager. Except as otherwise noted below, the information presented is current as of September 30, 2023. In each case, the dollar range listed may include shares owned by the portfolio manager through the manager’s self-directed account in Thornburg’s retirement plan. In addition to the holdings noted below, each of the portfolio managers is a participant in Thornburg’s profit sharing plan, which invests in shares of each of the Funds.

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held approximately 2% of the Class I shares of the Fund, and held less than 1% of the Class A or Class C shares of the Fund. As of December 31, 2023, the following persons were known to have held or record or beneficially 5% or more of Class A, Class C or Class I shares of the Fund:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held less than 1% of the Class A, Class C or Class I shares of the Fund. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class A, Class C or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held approximately 8% of the Class I shares of the Fund, and held less than 1% of the Class A and Class C shares of the Fund. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class C or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held less than 1% of the Class A, Class C or Class I shares of the Fund. As of December 31, 2023, the following persons were known to have held or record or beneficially 5% or more of Class A, Class C or Class I shares of the Fund:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held approximately 17% of the Class I shares of the Fund, and held less than 1% of the Class A and Class C shares of the Fund. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class A, Class C or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held approximately 21% of the Class I shares of the Fund, and held less than 1% of the Class A and Class C shares of the Fund. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class A, Class C or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held approximately 2% of the Class I shares of the Fund, and held than 1% of the Class A or Class C shares of the Fund. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of Class A, Class C or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held approximately 51% of the Class I shares of the Fund and held than 1% of the Class A shares of the Fund. As of December 31, 2023, Garrett Thornburg, 2300 North Ridgetop Road, Santa Fe, New Mexico 87506-8361, was the beneficial owner of approximately 47% of the Fund’s Class I shares. Shareholders that beneficially own more than 25% of the voting securities of a Fund could control the outcome of proposals presented to shareholders for approval. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class A or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held less than 1% of the Class A or Class I shares of the Fund. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class A or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held approximately 26% of the Class I shares of the Fund, and held less than 1% of the Class A, Class C or Class C2 shares of the Fund. As of December 31, 2023, Garrett Thornburg, 2300 North Ridgetop Road, Santa Fe, New Mexico 87506-8361, was the beneficial owner of approximately 26% of the Fund’s Class I shares. Shareholders that beneficially own more than 25% of the voting securities of a Fund could control the outcome of proposals presented to shareholders for approval. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class A, Class C, Class C2 or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held less than 1% of the Class A, Class C, Class C2 or Class I shares of the Fund. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class A, Class C, Class C2 or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held less than 1% of the Class A, Class C and Class I shares of the Fund. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class A, Class C or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held approximately 69% of the Class I shares of the Fund, and held less than 1% of the Class A shares of the Fund. As of December 31, 2023, Garrett Thornburg, 2300 North Ridgetop Road, Santa Fe, New Mexico 87506-8361, was the beneficial owner of approximately 69% of the Fund’s Class I shares. Shareholders that beneficially own more than 25% of the voting securities of a Fund could control the outcome of proposals presented to shareholders for approval. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class A or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held approximately 8% of the Class I shares of the Fund, and held less than 1% of the Class A, Class C or Class C2 shares of the Fund. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class A, Class C, Class C2 or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held approximately 35% of the Class I shares of the Fund, and held less than 1% of the Class A or Class D shares of the Fund. As of December 31, 2023, Garrett Thornburg, 2300 North Ridgetop Road, Santa Fe, New Mexico 87506-8361, was the beneficial owner of approximately 35% of the Fund’s Class I shares. Shareholders that beneficially own more than 25% of the voting securities of a Fund could control the outcome of proposals presented to shareholders for approval. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class A, Class D or Class I shares:

As of December 31, 2023, the officers and Trustees of Thornburg Investment Trust, as a group, held approximately 12% of the Class I shares of the Fund, and held less than 1% of the Class A or Class C shares of the Fund. As of December 31, 2023, the following persons were known to have held of record or beneficially 5% or more of the Fund’s Class A, Class C or Class I shares:

Each Fund will calculate its net asset value as of 4:00 p.m. Eastern Time on days when the New York Stock Exchange is open for trading, and more frequently if deemed desirable by the Fund. Net asset value will not be calculated on New Year’s Day, Washington’s Birthday (on the third Monday in February), Good Friday, Memorial Day (on the last Monday in May), Independence Day, Labor Day, Thanksgiving Day, Christmas Day, on the preceding Friday if any of the foregoing holidays falls on a Saturday, and on the following Monday if any of the foregoing holidays falls on a Sunday. Under the 1940 Act, net asset value must be computed at least once daily on each day (i) in which there is a sufficient degree of trading in a Fund’s portfolio securities that the current net asset value of its shares might be materially affected by changes in the value of such securities and (ii) on which an order for purchase or redemption of its shares is received.

Pursuant to a Distribution Agreement with Thornburg Investment Trust, Thornburg Securities LLC (“TSL”) (formerly known as Thornburg Securities Corporation (“TSC”)) acts as principal underwriter of each of the Funds. The Funds do not bear selling expenses except (i) those involved in registering its shares with the Securities and Exchange Commission and qualifying them or the Fund with state regulatory authorities, and (ii) expenses paid under the Service Plans and Distribution Plans which might be considered selling expenses. Terms of continuation, termination and assignment under the Distribution Agreement are identical to those described above with regard to the Investment Advisory Agreements, except that termination other than upon assignment requires six months’ notice.

Garrett Thornburg, Chairman and Trustee of Thornburg Investment Trust, is also director and controlling stockholder of TSL.

The following table shows the commissions and other compensation received by TSL (as TSC) from each of the Funds for the fiscal year or period ended September 30, 2023, except for amounts paid under Rule 12b-1 plans, which are described above under the caption “Service and Distribution Plans.”

No information is shown for the Core Plus Bond Fund because investment operations for the Fund commenced as of October 2, 2023.

Shares of the Funds are qualified for sale under the laws of every state or territory of the United States, except that the Shares of Limited Term California Fund, Intermediate New Mexico Fund and Intermediate New York Fund are only qualified for sale in California, New Mexico, and New York, respectively.

To the extent consistent with state and federal law, Redemption proceeds are normally paid in cash. Each Fund generally expects to meet redemption requests out of its holdings of cash, or by selling portfolio investments to generate cash to meet those requests. If considered appropriate by Thornburg, and subject to terms and conditions approved by the Trustees, a Fund may pay redemption proceeds in portfolio securities rather than cash.

The Funds have elected to pay in cash all requests for redemption by any shareholder. They may, however, limit such cash in respect to each shareholder during any 90-day period to the lesser of $250,000 or 1% of the net asset value of a Fund at the beginning of such period. This election has been made pursuant to Rule 18f-1 under the 1940 Act and is irrevocable while the Rule is in effect unless the Securities and Exchange Commission, by order, permits its withdrawal. If a Fund redeems shares by distributing portfolio securities, the shareholder would be subject to the risk of a subsequent adverse change in the market value of those securities, the brokerage and related costs of selling the securities, and the possibility that there is not a liquid market for some or all of the distributed securities.

Certain purchases of $1 million or more qualify for purchase without a sales charge, and Thornburg or TSL may pay compensation to financial advisors who place orders of $1 million or more, as more specifically described in the Funds’ Prospectus. However, to the extent shares of a fund purchased pursuant to this exception to the ordinary sales charge on Class A shares are held for more than 12 months but are redeemed less than 18 months after purchase, no compensation will be paid to financial advisors under this program for reinvestment otherwise qualifies for the exception to the sales charge for purchases of $1 million or more. Thornburg and TSL reserve the right to make judgments respecting these payments of compensation in reinvestment of redemption proceeds, in their reasonable discretion.

Class C shares of each Fund that have been held for eight years or more as of October 10, 2020 will convert to Class A shares of that same Fund at the close of business on that day. Thereafter, Class C and Class C2 shares of each Fund that have been held for eight years will convert to Class A shares of that Fund at the close of business on the tenth day (or, if that tenth day is not a business day, then on the next business day) of the month following the month in which the eighth anniversary occurred. For example, all Class C shares that have been held for eight years as of a date in November 2020 would convert to Class A shares at the close of business on December 10, 2020. The conversion of Class C or Class C2 shares to Class A shares will occur without the imposition of any sales charge, fee, or other charge. If you exchange the Class C shares of one Fund for Class C shares of another Fund or the Class C2 shares of one Fund for Class C2 shares of another Fund, the conversion period will be calculated from the date that you initially purchased your Class C or Class C2 shares, as applicable, not from the date of your exchange. If your account holds any Class C or Class C2 shares of a Fund that were purchased through the reinvestment of dividends or capital gain distributions (“distributed shares”), then each time your Class C or Class C2 shares are converted into Class A shares in accordance with the foregoing schedule, the Fund will also convert a pro rata portion of your distributed shares. Although the conversion of Class C or Class C2 shares to Class A shares is not expected to be a taxable event for federal income tax purposes based upon current guidance from the Internal Revenue Service, you should consult your tax advisor concerning the possible tax consequences of the conversion. If you hold your Class C or Class C2 shares through a financial intermediary, it is the responsibility of the financial intermediary to ensure that you are credited with the proper holding period for your Class C or Class C2 shares. The automatic conversion of Class C or Class C2 shares to Class A shares shall not apply to shares held through group retirement plan recordkeeping platforms of certain financial intermediaries who hold such shares with the Fund in an omnibus account and do not track participant level share lot aging to facilitate such a conversion.

The contingent deferred sales charge (CDSC) imposed on certain redemptions of Class A shares, and on redemptions Class C and Class C2 shares, will be waived in the event of the death of the shareholder (including a registered joint owner) occurring after the purchase of the shares redeemed. The CDSC imposed on redemptions Class C and Class C2 shares also will be waived for redemptions resulting from minimum required distributions made in connection with an IRA, Keogh Plan or a custodial account under Section 403(b) of the Code, or other qualified retirement plan, following attainment of age 70-1/2.

Some shareholders may hold shares of the Funds through fee-based programs, often referred to as “wrap accounts,” that are managed by investment dealers, financial advisors or other investment professionals (each, a “wrap account intermediary”). A wrap account intermediary may impose eligibility requirements on a shareholder’s participation in the fee-based program and ownership of shares through the program which are additional to the ownership requirements described in the applicable Prospectus. Under the terms of its fee-based program, a wrap account intermediary may also be permitted to effect a conversion (sometimes referred to as an “in-kind exchange”) of a shareholder’s shares in a Fund, including those shares purchased by the shareholder during the shareholder’s participation in the program, to a different class of shares of that Fund in situations when the shareholder no longer meets the wrap account intermediary’s stated eligibility requirements for the ownership of the class of shares that the shareholder initially purchased. For example, the terms of its fee-based program may permit a wrap account intermediary to effect this type of conversion when a shareholder moves his position in a class of shares of the Funds out of the program that offered that class of shares and into a program or account through which the wrap account intermediary only offers a different class or classes of shares of the Funds. Under other circumstances, a financial intermediary may effect this type of conversion with respect to new clients who held one class of shares of a Fund before becoming a client of the intermediary, and who are eligible for a wrap account through which the intermediary offers a different class of shares of the same Fund. Any such conversion by a wrap account intermediary will be made in accordance with the applicable Prospectuses of the Funds, and will be made without the imposition by the Funds of any sales load, fee or other charge. The class of shares that a shareholder owns after the conversion may bear higher fees and expenses than the class of shares that the shareholder initially purchased.

If you own shares of the Funds through a fee-based program, you should consult with your wrap account intermediary to determine whether there are any additional eligibility requirements that the wrap account intermediary imposes on your participation in their program and your ownership of the Funds’ shares through the program, and whether the wrap account intermediary prescribes any circumstances which may result in the type of share class conversion described herein.

Shares of one class of a Fund that are held through a broker-dealer or other financial intermediary may also be converted to shares of another class of that Fund under certain other circumstances, subject to TSL’s discretion and with TSL’s prior approval.

Thornburg believes, based upon current interpretations of law, that a shareholder’s exchange of shares of one class of a Fund for shares of a different class of the same Fund may, under certain circumstances, not result in the realization of gain or loss for federal income tax purposes. To determine whether you may be eligible for this type of tax-favored exchange, please contact Thornburg before redeeming your existing shares. You should also consult your own tax advisors with respect to the particular federal, state, local and foreign tax consequences of an exchange of shares.

Even if an exchange does not result in the realization of gain or loss for federal income tax purposes, any sales charges that you paid or that are payable on the shares you originally held (including any contingent deferred sales charges incurred upon redemption) will not be credited back to your account.

As described in the Prospectus, employees, officers, trustees, and directors of any Fund or Thornburg company, as well as the families of such persons and any trust established for the benefit of such persons or their families, are eligible to purchase Class I shares. In addition, pursuant to procedures adopted by the Trustees of Thornburg Investment Trust, the advisor is authorized to make Class I shares of the Funds available to certain categories of investors upon a determination by the advisor that the sale of Class I shares to that investor will not involve any sales expense to the Funds or to TSL, and is not expected to involve administrative services by the Fund or the advisor significantly exceeding the administrative services that are customarily provided to accounts that own Class I shares.

Thornburg and TSL have each adopted a business continuity plan that seeks to anticipate significant business disruptions to its operations, including disruptions to the securities markets due to terrorist attack. In accordance with this plan, Thornburg and TSL have each identified and made provision to recover all the critical systems required to protect its customers in the event of a significant business disruption.

PricewaterhouseCoopers LLP, whose principal business address is 300 Madison Avenue, New York, New York 10017, is the independent registered public accounting firm for the Funds.

Thornburg Investment Trust
Statement of Additional Information
Dated February 1, 2024 for

This Statement of Additional Information is not a prospectus but should be read in conjunction with the Funds’ “Thornburg Retirement Plan Shares” Prospectus dated February 1, 2024 (the “Prospectus”). A copy of the Prospectus and the most recent Annual and Semiannual Reports for each of the Funds may be obtained at no charge by contacting the administrator of your retirement plan, by telephoning a Fund Support Representative at 1-800-847-0200 or by writing to the distributor of the Funds’ shares, Thornburg Securities LLC, at 2300 North Ridgetop Road, Santa Fe, New Mexico 87506. The audited financial statements contained in the Annual Reports to Shareholders for each of the Funds for the fiscal year ended September 30, 2023 are incorporated herein by reference. No financial statements are available for the Core Plus Bond Fund because the Fund commenced investment operations as of October 2, 2023. This Statement of Additional Information is incorporated by reference into the Prospectus.

Global Opportunities Fund, International Equity Fund, International Growth Fund, Developing World Fund, Small/Mid Cap Core Fund, Small/Mid Cap Growth Fund, Investment Income Builder Fund, Limited Term U.S. Government Fund, Limited Term Income Fund, Core Plus Bond Fund and Strategic Income Fund are diversified series of Thornburg Investment Trust, a Massachusetts business trust (the “Trust”) organized on June 3, 1987 as a diversified, open-end management investment company under a Declaration of Trust (the “Declaration”). The Trust currently has 24 active Funds, 11 of which are the subject of this Statement of Additional Information. The Trustees are authorized to divide the Trust’s shares into additional series and classes.

The following discussion supplements the information in the Prospectus by providing additional detail about some of the investments that a Fund is generally permitted, but not required, to make in pursuing the Fund’s investment objective(s) and certain risks associated with those investments or to which a Fund may be otherwise subject. Not all of the investments identified below will be used by each Fund, and some investments that may be used by a Fund would not ordinarily be considered a principal investment strategy of the Fund. In general, a Fund may make any investment, including investments which are not identified below, if the investment advisor reasonably believes that the investment is consistent with the Fund’s investment objective(s) and policies and the Fund’s investment limitations do not expressly prohibit the Fund from doing so.

Global Opportunities Fund, International Equity Fund, International Growth Fund, Developing World Fund, Small/Mid Cap Core Fund, Small/Mid Cap Growth Fund, and Investment Income Builder Fund are sometimes referred to collectively in this Statement of Additional Information as the “Equity Funds.” Limited Term U.S. Government Fund, Limited Term Income Fund, Core Plus Bond Fund, and Strategic Income Fund are sometimes referred to collectively in this Statement of Additional Information as the “Fixed Income Funds.”

As discussed in the Prospectus, Limited Term U.S. Government Fund and Limited Term Income Fund seek to reduce changes in the value of their shares by maintaining a portfolio of investments with a certain dollar-weighted average maturity. A debt obligation’s maturity generally represents the time remaining until the principal amount of that obligation becomes due and payable.

such a security at the time of purchase by a Fund is likely to be substantially less than the maximum original maturity of the mortgage instruments underlying the security because of prepayments of the mortgage instruments, the passage of time from the issuance of the security until its purchase by a Fund and, in some cases, the wide dispersion of the original maturity dates of the underlying mortgage instruments.

Each of the Fixed Income Funds may from time to time seek to reduce changes in the value of its shares by maintaining a portfolio of investments with a particular dollar-weighted average duration, or may otherwise monitor a portfolio’s average duration. Duration is an estimate of the sensitivity of a debt obligation to changes in interest rates, and is consequently a measure of interest rate risk. The duration of a given debt obligation represents an approximation of the expected percentage change in a debt obligation’s value in response to a change in interest rates. Duration is commonly expressed as a number of years, and the value of an obligation or a portfolio of obligations with a higher number—a longer duration—will be more volatile in response to changes in interest rates.

Each of the Funds may purchase debt obligations which are of lower-quality at the time of purchase or which, due to issuer default or credit ratings downgrades, are determined subsequent to purchase to be of lower-quality. Under normal conditions, Core Plus Bond Fund may invest up to twenty five percent of its portfolio in such lower-quality debt obligations.

The Funds may also invest from time to time in unrated obligations. Unrated obligations may be less liquid than comparable rated obligations and may be more difficult to value. Moreover, unrated obligations may be more difficult for Thornburg to evaluate and there is the risk that Thornburg may not accurately evaluate an investment’s actual credit quality. In particular, an unrated obligation that Thornburg believes is equivalent to an investment grade obligation could ultimately exhibit characteristics associated with lesser rated obligations.

Mortgage-Backed Securities, Mortgage Pass-Through Securities and Asset-Backed Securities

Mortgage-Backed Securities. Each Fund may invest in mortgage-backed securities, in debt obligations which are secured with collateral consisting of mortgage-backed securities (see “Structured Finance Arrangements - Collateralized Mortgage Obligations” below), and in other types of mortgage-related securities.

Mortgage Pass-Through Securities. Limited Term Income Fund, Core Plus Bond Fund, Strategic Income Fund and each of the Equity Funds may also purchase pass-through pools of conventional mortgage loans that have been created by commercial banks, savings and loan institutions, private mortgage insurance companies, mortgage bankers and other secondary market issuers. Such issuers may, in addition, be the originators and/or servicers of the underlying mortgage loans as well as the guarantors of the mortgage-related

securities. Pools created by such non-governmental issuers generally offer a higher rate of interest than government and government-related pools because there are no direct or indirect government or agency guarantees of payments. Timely payment of interest and principal of these pools may be supported by various forms of insurance or guarantees, including individual loan, title, pool and hazard insurance and letters of credit. The insurance and guarantees are issued by governmental entities, private insurers and the mortgage poolers. Such insurance and guarantees and the creditworthiness of the issuers thereof will be considered in determining whether a mortgage-related security meets a Fund’s investment quality standards, if any. There can be no assurance that the private insurer or guarantors can meet their obligations under the insurance policies or guarantee arrangements. A Fund may buy mortgage-related securities without insurance or guarantees if, through an examination of the loan experience and practices of the originators/servicers and poolers, Thornburg determines that the securities meet the Fund’s quality standards. Although the market for such securities is becoming increasingly liquid, securities issued by certain private organizations may not be readily marketable.

Asset-Backed Securities. Limited Term Income Fund, Core Plus Bond Fund, Strategic Income Fund and each of the Equity Funds may invest in asset-backed securities.

One example of this type of asset-backed security is a Certificate of Automobile Receivables (“CARS”). CARS represent undivided fractional interests in a trust whose assets consist of a pool of motor vehicle retail installment sales contracts and security interests in the vehicles securing the contracts. Payments of principal and interests on CARS are passed through monthly to certificate holders, and are guaranteed up to certain amounts and for a certain time period by a letter of credit issued by a financial institution unaffiliated with the trustee or originator of the trust. An investor’s return on CARS may be affected by early prepayment of principal on the underlying vehicle sales contracts. If the letter of credit is exhausted, the trust may be prevented from realizing the full amount due on a sales contract because of state law requirements and restrictions relating to foreclosure sales of vehicles and the obtaining of deficiency judgments following such sales or because of depreciation, damage or loss of a vehicle, the application of federal and state bankruptcy and insolvency laws, or other factors. As a result, certificate holders may experience delays in payments or losses if the letter of credit is exhausted.

Asset-backed securities are often backed by a pool of assets representing the obligations of a number of different parties. To lessen the effect of failures by obligors on underlying assets to make payments, the securities may contain elements of credit support which fall into two categories: (i) liquidity protection; and (ii) protection against losses resulting from ultimate default by an obligor on the underlying assets. Liquidity protection refers to the provision of advances, generally by the entity administering the pool assets, to ensure that the receipt of payment on the underlying pool occurs in a timely fashion. Protection against losses results from payment of the insurance obligations on at least a portion of the assets in the pool by the issuer or sponsor from third parties, through various means of structuring the transaction or through a combination of such approaches. Limited Term Income Fund, as a possible purchaser of such securities, will not pay any additional or separate fees for credit support. The degree of credit support provided for each issue is generally based on historical information respecting the level of credit risk associated with the underlying assets. Delinquency or loss in excess of that anticipated or failure of the credit support could adversely affect the return on an investment in such a security.

Limited Term Income Fund, Core Plus Bond Fund, Strategic Income Fund and each of the Equity Funds may also invest in residual interests in asset-backed securities. In the case of asset-backed securities issued in a pass-through structure, the cash flow generated by the underlying assets is applied to make required payments on the securities and to pay related administrative expenses. The residual in an asset-backed security pass-through structure represents the interest in any excess cash flow remaining after making the foregoing payments. The amount of the residual will depend on, among other things, the characteristics of the underlying assets, the coupon rates on the securities, prevailing interest rates, the amount of administrative expenses and the actual prepayment experience on the underlying assets. Asset-backed security residuals not registered under the Securities Act of 1933 (the “1933 Act”) may be subject to certain restrictions on transferability. In addition, there may be no liquid market for such securities.

From time to time, proposals have been introduced before Congress for the purpose of restricting or eliminating the federal income tax exemption for interest on municipal securities. Similar proposals may be introduced in the future. These proposals, if enacted, may have the effect of reducing the availability of investments in municipal obligations and may adversely affect the value of a Fund’s portfolio. Although the interest received from municipal securities generally is exempt from federal income tax, a Fund may invest a portion of its total assets in municipal securities subject to the federal alternative minimum tax. Accordingly, investment in a Fund could cause noncorporate shareholders to be subject to (or result in an increased liability under) the federal alternative minimum tax. If this is the case, the Fund's net after-tax return to you may be lower.

of counsel. The credit quality of such investments will be determined by Thornburg at the time of purchase, and will be reviewed by Thornburg from time to time thereafter.

Tender Option Bonds. Each of the Funds may invest in tender option bonds. Tender option bonds are created when the owner or owners of one or more fixed rate municipal obligations sell or transfer those obligations to a trust that is sponsored by a broker- dealer or other third party. The trust then issues two new securities, each of which represents a beneficial interest in the trust. One of these securities is a short-term, floating-rate security, sometimes referred to as a “senior certificate” or a “floater.” The interest rate on the senior certificate is initially set at a level that is lower than the interest rate on the underlying municipal obligation(s), and resets periodically based on the movement of a short-term benchmark interest rate. The senior certificates also have a demand feature which permits the security holder to put the security back to the trust after a specified notice period. In that event the security holder is entitled to receive the principal amount of the senior certificate plus accrued interest. Those amounts are paid by either the sponsor of the trust or by a third party that acts as a liquidity provider for the trust. The other security issued by the trust is a long-term, floating-rate security, sometimes referred to as a “residual interest” or an “inverse floater.” The residual interests pay an interest rate equal to the interest that is paid on the underlying municipal obligation(s) less the interest that was paid to the holders of the senior certificates and less any expenses of the trust. Unlike the senior certificates, the residual interest securities do not have a put feature. Upon maturity of the underlying municipal obligation(s) or another event which causes the termination or liquidation of the trust, holders of the senior certificates are generally entitled to receive the principal amount of their security plus a portion of any gains in the market value of the underlying municipal obligations, while holders of the residual interest are generally entitled to receive whatever amounts remain in trust after payment to the senior certificate holders and payment of trust expenses.

certificates have a right to put those securities back to the trustee or to a third party liquidity facility, investments in senior securities are generally perceived as involving less interest rate, credit, and market risk than investments in the residual interests. Investors in senior certificates are, however, exposed to the risk that the trust sponsor or third party liquidity facility fails to meet its contractual obligation to buy back the security when the investor exercises its put option.

Collateralized Mortgage Obligations (“CMOs”). Each Fund may invest in CMOs.

The market for some CMOs may be less liquid than other debt obligations, making it difficult for a Fund to value its investment in the CMO or sell the CMO at an acceptable price.

Each Fund may also invest in CMOs issued by Freddie Mac. Like other CMOs, Freddie Mac CMOs are issued in multiple classes having different maturity dates. Freddie Mac CMOs are secured by the pledge of a pool of conventional mortgage loans purchased by Freddie Mac. Payments of principal and interest on the CMOs are typically made semiannually, as opposed to monthly. The amount of principal payable on each semiannual payment date is determined in accordance with Freddie Mac’s mandatory sinking fund schedule, which, in turn, is equal to approximately 100% of the Federal Housing Administration prepayment experience applied to the mortgage collateral pool. All sinking fund payments in the CMOs are allocated to the retirement of the individual classes of bonds in the order of their stated maturities. Payment of principal on the mortgage loans in the collateral pool in excess of the amount of Freddie Mac’s minimum sinking fund obligation for any payment date are paid to the holders of the CMOs as additional sinking fund payments. Because of the “pass-through” nature of all principal payments received on the collateral pool in excess of Freddie Mac’s minimum sinking fund requirement, the rate at which principal of the CMOs is actually repaid is likely to be such that each class of bonds will be retired in advance of its scheduled date. If collection of principal (including prepayments) on the mortgage loans during any semiannual payment period is not sufficient to meet Freddie Mac’s minimum sinking fund obligation on the next sinking fund payment date, Freddie Mac agrees to make up the deficiency from its general funds. Criteria for the mortgage loans in the pool backing the CMOs are identical to those of Freddie Mac PCs. Freddie Mac has the right to substitute collateral in the event of delinquencies or defaults.

Other Structured Finance Arrangements. Each of the Equity Funds, Limited Term Income Fund, Core Plus Bond Fund, and Strategic Income Fund may also invest in other types of structured finance arrangements besides CMOs.

The risks of investment in a CDO depend largely on the type of collateral securities and the class of the CDO in which a Fund invests. Normally, CBOs, CLOs and other CDOs are privately offered and sold, and thus, are not registered under the securities laws. As a result, investments in CDOs may be characterized by a Fund as illiquid investments. However, an active dealer market may exist for CDOs, which may allow a CDO to qualify for resale to qualified institutional buyers pursuant to Rule 144A under the 1933 Act. In addition to the normal risks associated with fixed income securities described elsewhere in this Statement of Additional Information and the Prospectus (e.g., interest rate risk and credit risk), CDOs carry additional risks including, but not limited to: (i) the possibility that distributions from collateral securities will not be adequate to make interest or other payments; (ii) the qualify of the collateral may decline in value or default; (iii) the Fund may invest in tranches of CDOs that are subordinate to other tranches; (iv) the complex structure of the security may not be fully understood at the time of investment and may produce disputes with the issuer or unexpected investment results; and (v) the CDO’s manager may perform poorly.

U.S. Government Obligations include bills, certificates of indebtedness, notes and bonds issued or guaranteed as to principal or interest by the United States or by agencies or authorities controlled or supervised by and acting as instrumentalities of the U.S. government and established under the authority granted by Congress, including, but not limited to, Ginnie Mae, the Tennessee Valley Authority, the Bank for Cooperatives, the Farmers Home Administration, Federal Home Loan Banks, Federal Intermediate Credit Banks, Federal Land Banks, Farm Credit Banks and Fannie Mae. Some obligations of U.S. government agencies, authorities and other instrumentalities are supported by the full faith and credit of the U.S. Treasury; others by the right of the issuer to borrow from the Treasury; others only by the credit of the issuing agency, authority or other instrumentality. In the case of securities not backed by the full faith and credit of the United States, the investor must look principally to the agency issuing or guaranteeing the obligation for ultimate repayment, and may not be able to assert a claim against the United States itself in the event the agency or instrumentality does not meet its commitments. All U.S. Government Obligations are subject to the same risks affecting other debt obligations. Even if a U.S. Government Obligation is backed by the full faith and credit of the U.S. Treasury, it is possible that the U.S. government may be unable or unwilling to repay principal and interest when due, and may require that the terms for payment be renegotiated.

Each of the Funds may purchase zero coupon bonds, including stripped securities.

Equity securities represent an ownership interest in the entity issuing the security. Common stocks, the most familiar type of equity security, represent an ownership interest in a corporation. The values of equity securities fluctuate significantly in response to changes in market conditions, political and economic news, changes in company earnings and dividends, changes in the prospects for company businesses, industry and technological developments, changes in interest rates, and developments affecting specific companies. When equity securities held by a Fund decline in value, the value of the Fund’s shares declines. These declines may be significant and there is no assurance that declines in value can be recaptured by future gains in value. When equity securities held in short positions by a Fund increase in value, the Fund may experience a loss, as described in “Short Sales,” below.

Each of the Equity Funds and Strategic Income Fund may invest in the shares of closed end funds, including closed end funds which have elected to be treated as business development companies under the Investment Company Act of 1940 (the “1940 Act”).

Each of the Equity Funds, Limited Term Income Fund, Core Plus Bond Fund, and Strategic Income Fund may invest in convertible debt obligations, and each of the Equity Funds and Strategic Income Fund may also invest in convertible preferred equity securities.

market value can be influenced by several factors, a convertible debt obligation will not be as sensitive to interest rate changes as a similar non-convertible debt obligation, and generally will have less potential for gain or loss than the underlying stock.

Each of the Equity Funds, Core Plus Bond Fund, and Strategic Income Fund may invest in the shares of exchange traded funds (“ETFs”).

Each of the Equity Funds and Strategic Income Fund may invest in common stock or other equity securities offered through initial public offerings (“IPOs”).

Each of the Equity Funds and Strategic Income Fund may invest in interests issued by limited partnerships and master limited partnerships (“MLPs”). MLPs are business enterprises in which ownership interests are publicly traded, and which typically own interests in properties or businesses related to the oil and gas industries, although they may own other types of investments. Ownership interests in limited partnerships other than MLPs may not be publicly traded, which may decrease the liquidity of those investments. Investments in MLPs and other limited partnerships are subject to the risks associated with equity investments generally and to the risks associated with the specific industry or industries in which the partnership operates. Investments in MLPs and other limited partnerships are also subject to certain additional risks when compared to investments in corporations, including certain tax risks, a more limited ability for investors to elect or remove the issuer's management, and more limited voting rights for investors.

Each of the Equity Funds, Limited Term Income Fund, and Strategic Income Fund may invest in preferred stock.

Each of the Equity Funds and Strategic Income Fund may invest in real estate investment trusts (“REITS”).

Each of the Equity Funds and Strategic Income Fund may enter into short sales with respect to an investment that Thornburg believes to be overvalued or to hedge against the Fund’s long exposures. The Fund may engage in short selling with respect to any of the securities in which the Fund is permitted to invest, including domestic and foreign equity securities and debt obligations.

Although the Fund hopes to profit from its short sales, short sales may include risks that are different than, and in some respects may exceed, the Fund’s long investments. Because there is no limitation on the amount to which the price of a security may increase between the date that the Fund borrows it from the lender and the date that the Fund must purchase the security on the open market to deliver it to the lender, the losses that the Fund incurs from a short sale are potentially limitless. In contrast, the losses that the Fund may realize on its long positions cannot exceed the total amount of the Fund’s investments in those positions. The lender in a short sale transaction may have a right to require the Fund to return the borrowed securities earlier than scheduled, in which case the Fund may have to purchase the securities on the open market at a time when the securities’ prices are unfavorable. To the extent the Fund is required to deliver collateral to the lender in response to declines in the value of the Fund’s short positions, the Fund may have to sell other securities in its portfolio to meet those collateral requirements. Such sales may not be at favorable prices, or may impede the pursuit of the Fund’s investment strategy.

Subject to certain limitations, as described in “Investment Limitations” below, each of the Equity Funds, Limited Term Income Fund and Strategic Income Fund may invest in warrants and similar rights. A warrant represents an option to purchase a stated number

of shares of common stock of an issuer at a specified price during a specified period of time. The prices of warrants will not always correlate with the prices of the underlying shares of stock. In addition to the risks relating to the underlying stock, the purchase of warrants involves the risk that the effective price paid for the warrant, when added to the subscription price of the underlying stock, will exceed the market price of the underlying stock. Rights represent a preemptive right to purchase additional shares of an issuer’s common stock at the time of a new offering of those shares, thereby permitting the rights holder to retain the same ownership percentage after the new offering.

Each of the Equity Funds, Limited Term Income Fund and Strategic Income Fund may make investments in foreign debt obligations or foreign equity securities, and Core Plus Bond Fund may make investments in foreign debt obligations.. International Equity Fund, International Growth Fund, and Developing World Fund invest primarily in foreign securities, Global Opportunities Fund invests in a portfolio of both domestic and foreign securities, and at times the portfolios of other Funds may contain a significant percentage of foreign securities.

Each of the Equity Funds, Limited Term Income Fund, Core Plus Bond Fund, and Strategic Income Fund may conduct foreign currency transactions on a spot (i.e., cash) basis or by entering into forward contracts and futures contracts to purchase or sell foreign currencies at a future date and price. Additional detail about foreign currency transactions is provided below in the sections entitled “Investing in Derivative Instruments - Foreign Currency Transactions,” “Investing in Derivative Instruments - Futures Contracts - Futures Relating to Foreign Currencies,” “Investing in Derivative Instruments - Options - Options Relating to Foreign Currencies,” and “Investing in Derivative Instruments - Swap Agreements, Caps, Floors and Collars - Currency Swaps.”

Any Fund which is permitted to purchase or sell forward contracts, futures contracts and options (see “Forward Contracts”, “Futures Contracts” and “Options” below) may also purchase and sell such forward contracts, futures contracts and options in combination with one another in order to adjust the risk and return characteristics of the overall position. For example, a Fund may purchase a put option and write a call option on the same underlying instrument, in order to construct a combined position whose risk and return characteristics are similar to selling a futures contract. Another possible combined position would involve writing a call option at one strike price and buying a call option at a lower price, in order to reduce the risk of the written call option in the event of a substantial price increase. Because combined options positions involve multiple trades, they result in higher transaction costs and may be more difficult to open and close out. A combined transaction will usually contain elements of risk that are present in each of its component transactions. Although combined transactions are normally entered into based on Thornburg’s judgment that the combined strategies will reduce risk or otherwise more effectively achieve the desired portfolio management goal, it is possible that the combination will instead increase such risks or hinder achievement of the goal.

Each of the Equity Funds, Limited Term Income Fund, Core Plus Bond Fund, and Strategic Income Fund may make investments in Euro dollar instruments.

Limited Term Income Fund, Core Plus Bond Fund, Strategic Income Fund and each of the Equity Funds may conduct foreign currency transactions on a spot (i.e., cash) basis or by entering into forward contracts to purchase or sell foreign currencies at a future date and price.

Currency Forward Contracts. A currency forward contract is a privately negotiated obligation to purchase or sell a specific currency at a future date, which may be any fixed number of days from the date of the contract agreed upon by the parties, at a price set at the time of the contract. The parties to a forward contract may agree to offset or terminate the contract before its maturity, or may hold the contract to maturity and complete the contemplated currency exchange. A Fund may use currency forward contracts for any purpose consistent with its investment objectives. The following discussion summarizes the principal currency management strategies

involving forward contracts that could be used by a Fund. A Fund may also use swap agreements, indexed securities, and options and futures contracts relating to foreign currencies for the same purposes.

In those instances when a Fund enters into a forward currency contract, it typically does so for portfolio hedging purposes. In that regard, a Fund may enter into a forward contract to sell a foreign currency in which certain of its portfolio investments are denominated as a strategy to reduce the risk that a decline in the value of the foreign currency relative to the U.S. dollar will diminish the value of the portfolio investments denominated in that foreign currency. For example, if a Fund owned securities denominated in pounds sterling, it could enter into a forward contract to sell pounds sterling in return for U.S. dollars to hedge against possible declines in the pound’s value. Such a hedge, sometimes referred to as a “position hedge,” would tend to offset both positive and negative currency fluctuations, but would not offset changes in security values caused by other factors. A Fund could also hedge the position by selling another currency expected to perform similarly to the pound sterling. This type of hedge, sometimes referred to as a “proxy hedge,” could offer advantages in terms of cost, yield, or efficiency, but generally would not hedge currency exposure as effectively as a simple hedge into U.S. dollars. Proxy hedges may result in losses if the currency used to hedge does not perform similarly to the currency in which the hedged securities are denominated. A Fund could use a similar hedging strategy in an “indirect hedge” with respect to securities holdings that are denominated in U.S. dollars or another currency, but which do a substantial amount of business in a given foreign currency and are consequently exposed to a risk that the value of that foreign currency will decline relative to the U.S. dollar or other currency in which the holding is denominated. The Funds do not enter into hedging transactions in all instances when it might be desirable to do so, and any Fund may be exposed to currency risk some or most of the time without any hedging position for purposes of reducing that risk.

In another circumstance, a Fund that has agreed to buy or sell a security denominated in a foreign currency may seek to “lock in” the U.S. dollar price of the security by entering into a forward contract to buy or sell the relevant foreign currency for a fixed amount of U.S. dollars. This technique, sometimes referred to as a “settlement hedge” or “transaction hedge,” is intended to protect a Fund against an adverse change in foreign currency values between the date the security is purchased or sold and the date on which payment is made or received. A Fund also may enter into forward contracts to purchase or sell a foreign currency in anticipation of future purchases or sales of securities denominated in foreign currency, even if the specific investments have not yet been selected by Thornburg.

Each of the Equity Funds, Limited Term Income Fund, Core Plus Bond Fund, and Strategic Income Fund may purchase or sell futures contracts to hedge against anticipated interest rate, currency or market changes, for duration management or risk management purposes, or to enhance potential income and gains.

Distributions to shareholders associated with income or net gains realized by a Fund from transactions in futures contracts (or options on futures contracts) may be subject to federal income tax.

Margin Payments. The purchaser or seller of a futures contract is not required to deliver or pay for the underlying instrument unless the contract is held until the delivery date. However, in any instance when a Fund enters into a futures contract, either as purchaser or as seller, the Fund will segregate with its custodian or with a futures commission merchant (“FCM”) as initial margin assets sufficient to meet its obligations under the contract. The Fund will also deposit daily “variation margin” payments as required during the term of the contract in order settle the change in the contract’s value on a daily basis (a process known as “marking to market”). Segregated assets may consist of cash, cash equivalents or high grade liquid debt obligations, or other assets agreed to by the parties to the futures contract. Initial and variation margin payments do not constitute purchasing securities on margin for purposes of a Fund’s investment limitations. In the event of the bankruptcy of a FCM that holds margin on behalf of a Fund, the Fund may be entitled to return of margin owed to it only in proportion to the amount received by the FCM’s other customers, potentially resulting in losses to the Fund.

futures in conjunction with each other or with currency options or forward contracts. Currency futures values can be expected to correlate with exchange rates, but may not reflect other factors that affect the value of the Fund’s investments. A currency hedge, for example, should protect a Yen-denominated security from a decline in the Yen, but will not protect the Fund against a price decline resulting from deterioration in the issuer’s creditworthiness. Because the value of each Fund’s foreign-denominated investments changes in response to many factors other than exchange rates, it may not be possible to match the amount of currency futures to the value of the Fund’s investments exactly over time. See “Foreign Currency Transactions” above.

Each of the Equity Funds, Core Plus Bond Fund, and Strategic Income Fund may purchase securities whose prices are indexed to the prices of other securities, securities indices, currencies, precious metals or other commodities or other financial indicators.

Each of the Equity Funds, Limited Term Income Fund, Core Plus Bond Fund, and Strategic Income Fund may purchase or write put and call options to hedge against anticipated interest rate or market changes, for duration management or risk management purposes, or to enhance potential income and gains.

Writing Put and Call Options. When a Fund sells or “writes” a put option, it takes the opposite side of the transaction from the option’s purchaser. In return for receipt of the premium, a Fund, as writer of such an option, would be obligated to pay the strike price for the option’s underlying instrument if the other party to the option chooses to exercise it. When writing an option on a futures contract, a Fund would be required to make margin payments to cover the Fund’s potential obligation to pay the strike price if the other party chooses to exercise the option. A Fund may seek to terminate its position in a put option it writes before it is exercised by closing out the option in the secondary market at its then current price. If, however, the secondary market is not sufficiently liquid, the Fund may not be able to close out its position and would, therefore, remain obligated to purchase the underlying instrument at the strike price if the option is exercised. If the price of the underlying instrument rises, the writer of a put ordinarily will profit by the amount of the premium received on writing the option. If the price of the instrument declines, the writer may experience a loss, although the amount of the loss is offset to some degree by the amount of the premium received.

and liquidity if their strike prices are not close to the underlying instrument’s current price. In addition, exchanges may establish daily price fluctuation limits for options, and may halt trading if a contract’s price moves upward or downward more than the limit in a given day. On volatile trading days when the price fluctuation limit is reached or a trading halt is imposed, it may be impossible for a Fund to enter into new positions or close out existing positions. If the secondary market for a contract is not liquid because of price fluctuation limits or otherwise, it could prevent prompt liquidation of unfavorable positions, and potentially could require the Fund to continue to hold a position until delivery or expiration regardless of changes in its value. As a result, the Fund’s access to other assets held to cover its options positions could also be impaired.

Each of the Equity Funds, Limited Term Income Fund, Core Plus Bond Fund, and Strategic Income Fund may invest in structured notes.

principal amount payable upon maturity or redemption may increase or decrease, depending upon changes in the value of the reference asset. The terms of a structured note may provide that, in certain circumstances, no principal is due at maturity and, therefore, may result in a loss of invested capital by a Fund. Structured notes may be indexed positively or negatively, so that appreciation of the reference asset may produce an increase or decrease in the interest rate or value of the principal at maturity. In addition, changes in the interest rate or the value of the principal at maturity may be fixed at a specified multiple of the change in the value of the reference asset, making the value of the note particularly volatile.

Each of the Equity Funds, Limited Term Income Fund, Core Plus Bond Fund, and Strategic Income Fund may enter into swap agreements and related caps, floors and collars. None of these Funds are limited to any particular form of swap agreement, provided that Thornburg determines that the agreement it is consistent with the Fund’s investment objective and policies.

The following contains additional detail about certain other investments a Fund may make and certain other risks to which a Fund may be subject.

Consideration of Environmental, Social and Governance (“ESG”) Characteristics

When evaluating a potential investment opportunity, each of the Funds may consider the issuer’s ESG characteristics. Thornburg defines a significant ESG characteristic as one which may materially affect an issuer’s risk and return profile and, accordingly, the issuer’s long-term investment performance. In this way, Thornburg’s consideration of ESG characteristics is no different than its consideration of more traditional financial metrics or other factors which may affect the risks and returns of a Fund’s investments. The specific ESG characteristics which Thornburg determines to be significant will vary over time and among different financial sectors and industries, but will generally include environmental, social capital, human capital, business model and innovation, and leadership and governance characteristics. Examples of potentially significant environmental characteristics include: greenhouse gas emissions; air quality; energy management; water and wastewater management; waste and hazardous materials management; and ecological impacts. Examples of potentially significant social capital characteristics include: human rights and community relations; customer privacy; data security; access & affordability; product quality and safety; customer welfare; and selling practice and product labeling. Examples of potentially significant human capital characteristics include: labor practices; employee health & safety; and employee engagement, diversity and inclusion. Examples of potentially significant business model and innovation characteristics include: product design and lifecycle management; business model resilience; supply chain management; materials sourcing and efficiency; and the physical impacts of climate change. Examples of potentially significant leadership and governance characteristics include: business ethics; competitive behavior; management of the legal and regulatory environment; critical risk management; and systemic risk management.

Each Fund except Limited Term U.S. Government Fund may also invest a portion or all of the Fund’s daily cash balance in Thornburg Capital Management Fund, a separate series of the Trust (the “Capital Management Fund”). The Capital Management Fund’s

shares are not publicly available. The Capital Management Fund is not a money market fund and does not seek to maintain a stable net asset value of $1.00. The Capital Management Fund seeks current income consistent with liquidity management and safety of capital. To pursue that investment objective, the Capital Management Fund invests principally in short-term obligations which are determined by Thornburg to be of high quality including, but not limited to, obligations issued by U.S. and foreign companies, U.S. and foreign banks, U.S. and foreign governments, U.S. agencies, states, and municipalities, and international organizations such as the World Bank and the International Monetary Fund, and repurchase agreements based on those obligations. The Capital Management Fund does not currently pay a separate investment advisory fee or administrative services fee to Thornburg, but Funds which invest in the Capital Management Fund would indirectly bear the other operating expenses of the Capital Management Fund. Those indirect expenses are similar to the expenses paid by other businesses owned by the Funds, are not direct costs paid by Fund shareholders, are not used to calculate a Fund’s net asset value, and have no impact on the costs associated with Fund operations.

Each Fund may under certain circumstances purchase bank certificates of deposit. Each Municipal Fund may invest in certificates of deposit of domestic banks with assets of $1 billion or more as part of the Fund’s permitted “temporary investments” (see “Temporary Investments” below). Limited Term U.S. Government Fund may invest up to 20% of its assets in: (i) certificates of deposit maturing in one year or less after the date of acquisition and issued by domestic banks with assets of $1 billion or more; and (ii) certificates of deposit insured as to principal by the Federal Deposit Insurance Corporation. If any certificate of deposit in which Limited Term U.S. Government Fund invests (whether or not insured in whole or in part) is nonnegotiable and matures in more than seven days, the certificate of deposit will be deemed by Limited Term U.S. Government Fund to be illiquid and will, therefore, be subject to the Fund’s investment restriction respecting investment in illiquid investments. Limited Term Income Fund may invest in certificates of deposit of domestic and foreign banks with assets of $1 billion or more, including foreign branches of domestic banks. Limited Term Income Fund may also invest in certificates of deposit issued by banks and savings and loan institutions with assets of less than $1 billion, provided that (i) the principal amounts of such certificates of deposit are insured by an agency of the U.S. Government, (ii) at no time will the Fund hold more than $100,000 principal amount of certificates of deposit of any one such bank, and (iii) at the time of acquisition, no more than 10% of the Fund’s assets (taken at current value) are invested in certificates of deposit of such banks. Strategic Income Fund and each of the Equity Funds may invest in certificates of deposit issued by domestic and foreign banks, including foreign branches of domestic banks.

settlement made at each renewal without physical delivery of securities. Moreover, the transaction may be preceded by a firm commitment agreement pursuant to which a Fund agrees to buy a security on a future date.

Each Fund may enter into reverse repurchase agreements. Neither Limited Term U.S. Government Fund nor Income will enter into a reverse repurchase agreement if, as a result, more than 5% of the Fund’s total assets would then be subject to reverse repurchase agreements.

Each Fund may lend securities to parties such as broker-dealers or institutional investors. Securities lending allows a Fund to retain ownership of the securities loaned and, at the same time, to earn additional income. Since there may be delays in the recovery of loaned securities, or even a loss of rights in collateral supplied should the borrower fail financially, loans will be made only to parties deemed by Thornburg to be of good standing. Furthermore, they will only be made if, in Thornburg’s judgment, the consideration to be earned from such loans would justify the risk.

Global Opportunities Fund, International Equity Fund, International Growth Fund, Small/Mid Cap Core Fund, Small/Mid Cap Growth Fund, Investment Income Builder Fund, and Strategic Income Fund

that Fund. Strategic Income Fund, Small/Mid Cap Core Fund, International Equity Fund, Small/Mid Cap Growth Fund, International Growth Fund, Investment Income Builder Fund, or Global Opportunities Fund may not:

(4) underwrite any issue of securities (except to the extent that the Fund may be deemed to be an underwriter within the meaning of the 1933 Act in the disposition of restricted securities);

The following investment limitations are not fundamental and may be changed without shareholder approval as to each Fund:

(ix) The Fund does not currently intend to invest in oil, gas or other mineral exploration or development programs or leases.

(3) underwrite any issue of securities (except to the extent that the Fund may be deemed to be an underwriter within the meaning of the 1933 Act in the disposition of portfolio securities);

by such obligations, generally described (but not limited) in the Prospectus, and then only in the nongovernmental obligations described in the Prospectus;

(3) Borrow money, except (a) as a temporary measure, and then only in amounts not exceeding 5% of the value of the Fund’s total assets or (b) from banks, provided that immediately after any such borrowing all borrowings of the Fund do not exceed 10% of the Fund’s total assets. The exceptions to this restriction are not for investment leverage purposes but are solely for extraordinary or emergency purchases or to facilitate management of the Fund’s portfolio by enabling the Fund to meet redemption requests when the liquidation of portfolio instruments is deemed to be disadvantageous. The Fund will not purchase securities while borrowings are outstanding. For purposes of this restriction (i) the security arrangements described in restriction (4) below will not be considered as borrowing money, and (ii) reverse repurchase agreements will be considered as borrowing money;

(5) Underwrite any issue of securities, except to the extent that, in connection with the disposition of portfolio securities, it may be deemed to be an underwriter under federal securities laws;

(14) Purchase securities of other investment companies, except in connection with a merger, consolidation, reorganization or acquisition of assets;

(17) Enter into any reverse repurchase agreement if, as a result thereof, more than 5% of its total assets would be subject to its obligations under reverse purchase agreements at any time;

Whenever an investment policy or restriction states a minimum or maximum percentage of the Limited Term U.S. Government Fund’s assets which may be invested in any security or other assets, it is intended that the minimum or maximum percentage limitations will be determined immediately after and as a result of the Fund’s acquisition of the security or asset. Accordingly, any later increase or decrease in the relative percentage of value represented by the asset or security resulting from changes in asset values will not be considered a violation of these restrictions.

In applying the percentage restrictions on the Limited Term U.S. Government Fund’s investments described under the caption “Principal Investment Strategies” in the Fund’s Prospectuses, and in applying the restriction described in paragraph (1), above, “assets” is understood to mean net assets plus borrowings for investment purposes.

estate acquired as a result of the Fund’s ownership of securities) or purchase or sell physical commodities or contracts relating to physical commodities;