Loomis Sayles Funds I

Before you invest, you may want to review the Fund’s Prospectus, which contains more information about the Fund and its risks. You can find the Fund’s Prospectus and other information about the Fund online at http://loomissayles.com/Internet/Internet.nsf/ ReportMatrix?Open&Channel=MF&Page=Prospectus&Doc=PDF. You can also get this information at no cost by calling 800-633-3330 or by sending an e-mail request to FundInformation@loomissayles.com.The Fund’s Prospectus and Statement of Additional Information (“SAI”), each dated February 1, 2011 are incorporated by reference into this Summary Prospectus.

The Fund’s investment objective is high total investment return through a combination of current income and capital appreciation.

The following table describes the fees and expenses that you may pay if you buy and hold shares of the Fund.


ANNUAL FUND OPERATING EXPENSES (expenses that you pay each year as a percentage of the value of your investment)	Institutional Class	Retail Class	Admin Class
Management fees	0.51%	0.51%	0.51%
Distribution and/or service (12b-1) fees	0.00%	0.25%	0.25%
Other expenses¹	0.13%	0.18%	0.45%²
Total annual fund operating expenses	0.64%	0.94%	1.21%
Fee waiver and/or expense reimbursement³	0.00%	0.00%	0.01%
Total annual fund operating expenses after fee waiver and/or expense reimbursement	0.64%	0.94%	1.20%

The example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your shares at the end of those periods. The example also assumes that your investment has a 5% return each year and the Fund’s operating expenses remain the same. The example for Admin Class shares is based upon the Total Annual Fund Operating Expenses After Fee Reduction and/or Expense Reimbursement for the 1-year period and on the Total Annual Fund Operating Expenses for the remaining periods. The examples for Retail and Institutional Class shares are based on the Total Annual Fund Operating Expenses for all periods. Although your actual costs may be higher or lower, based on these assumptions your costs would be:


	1 year	3 years	5 years	10 years
Institutional Class	$ 65	$205	$357	$ 798
Retail Class	$ 96	$300	$520	$1,155
Admin Class	$122	$383	$664	$1,465

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes for you if your Fund shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the example, affect the Fund’s performance. During its most recently ended fiscal year, the Fund’s portfolio turnover rate was 27% of the average value of its portfolio.

Under normal circumstances, the Fund will invest at least 80% of its net assets (plus any borrowings made for investment purposes) in fixed-income securities. The Fund will invest primarily in investment-grade fixed-income securities, although it may also invest up to 35% of its assets in below investment-grade fixed-income securities (commonly known as “junk bonds”) and up to 20% of its assets in equity securities such as common stocks and preferred stocks (with up to 10% of its assets in common stocks). Below investment-grade fixed-income securities are rated below investment-grade quality (i.e., none of the three major rating agencies (Moody’s Investors Service, Inc., Fitch Investor Services, Inc. or Standard & Poor’s Ratings Group) have rated the securities in one of their respective top four ratings categories). The Fund’s fixed-income securities investments may include unrated securities (securities that are not rated by a rating agency) if Loomis Sayles determines that the securities are of comparable quality to rated securities that the Fund may purchase. The Fund may invest in fixed-income securities of any maturity.

In deciding which securities to buy and sell, Loomis Sayles may consider a number of factors related to the bond issue and the current bond market, for example, the stability and volatility of a country’s bond markets, the financial strength of the issuer, current interest rates, Loomis Sayles’ expectations regarding general trends in interest rates and currency considerations. Loomis Sayles will also consider how purchasing or selling a bond would impact the overall portfolio’s risk profile (for example, its sensitivity to currency risk, interest rate risk and sector-specific risk) and potential return (income and capital gains).

Three themes typically drive the Fund’s investment approach. First, Loomis Sayles generally seeks fixed-income securities of issuers whose credit profiles it believes are improving. Loomis Sayles’ credit research team provides deep fundamental and quantitative analysis as well as ratings on over 1,000 issuers worldwide. The broad coverage combined with the objective of identifying attractive investment opportunities makes this an important component of the investment approach. Second, the Fund makes significant use of non-market-related securities in an effort to diversify the portfolio away from prevalent systemic risks. These securities may not have a direct correlation with changes in interest rates, thus helping to manage interest rate risk and to offer diversified sources for return. Third, Loomis Sayles analyzes different sectors of the economy and differences in the yields (“spreads”) of various fixed-income securities (U.S. governments, investment-grade corporates, securitized assets, high-yield corporates, emerging markets, non-U.S. sovereigns and credits, convertibles, bank loans and municipals) in an effort to find securities that it believes may produce attractive returns for the Fund in comparison to their risk.

The Fund may invest any portion of its assets in securities of Canadian issuers and up to 20% of its assets in other foreign securities, including emerging markets securities. The Fund may invest without limit in obligations of supranational entities (e.g., the World Bank).

The fixed-income securities in which the Fund may invest include, among other things, corporate bonds and other debt securities, U.S. government securities, commercial paper, zero-coupon securities, mortgage-related securities (including senior and junior loans, mortgage dollar rolls, stripped mortgage-related securities and collateralized mortgage obligations) and other asset-backed securities, when-issued securities, real estate investment trusts (“REITs”), Rule 144A securities, structured notes, repurchase agreements and convertible securities. The Fund may engage in options and futures transactions, foreign currency transactions, swap transactions (including credit default swaps) and other derivative transactions.

The principal risks of investing in the Fund are summarized below. The Fund does not represent a complete investment program. You may lose money by investing in the Fund.

Below Investment-Grade Fixed-Income Securities Risk is the risk that the Fund’s investments in below investment-grade fixed-income securities may be subject to greater risks than other fixed-income securities, including being subject to greater levels of interest rate risk, credit risk (including a greater risk of default) and liquidity risk. The ability of the issuer to make principal and interest payments is predominantly speculative for below investment-grade fixed-income securities.

Credit Risk is the risk that companies in which the Fund invests, or with which it does business, will fail financially or otherwise be unwilling or unable to meet their obligations to the Fund.

Currency Risk is the risk that the value of the Fund’s investments will fall as a result of changes in exchange rates. Loomis Sayles may elect not to hedge currency risk, which may cause the Fund to incur losses that would not have been incurred had the risk been hedged.

Derivatives Risk is the risk that the value of the Fund’s derivative investments such as forward currency contracts, options and futures transactions and swap transactions will fall, for example, because of changes in the value of the underlying reference instruments, pricing difficulties or lack of correlation with the underlying investments. There is also the risk that the Fund may be unable to terminate or sell a derivatives position at an advantageous time or price. Moreover, there can be no assurance that the Fund’s derivative counterparties will not experience financial difficulties, possibly resulting in losses to the Fund. This risk is greater for forward currency contracts, swaps and other over-the-counter traded derivatives. Investing in derivatives gives rise to other risks, such as leverage risk, liquidity risk, credit risk, counterparty risk, interest-rate risk and market risk.

Emerging Markets Risk is the risk that the Fund’s investments may face greater foreign securities risk. Investing in companies traded in emerging securities markets, which may be smaller and have shorter operating histories than companies in developed markets, involves risks in addition to, and greater than, those generally associated with investing in developed foreign markets. The extent of economic development, political stability, market depth, infrastructure, capitalization and regulatory oversight in emerging market economies is generally less than in more developed markets.

Equity Securities Risk is the risk that the value of a stock may decline for a number of reasons which relate directly to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods and services, or the equity markets generally.

Extension Risk is the risk that an unexpected rise in interest rates will extend the life of a mortgage- or asset-backed security beyond the expected prepayment time, typically reducing the security’s value.

Foreign Securities Risk is the risk that the value of the Fund’s foreign investments will fall as a result of foreign political, social, economic or currency changes or other issues relating to foreign investing generally.

Inflation/Deflation Risk is the risk that the value of assets or income from investments will be worth less in the future as inflation decreases the present value of future payments. Deflation risk is the risk that prices throughout the economy decline over time - the opposite of inflation. Deflation may have an adverse effect on the creditworthiness of issuers and may make issuer default more likely, which may result in a decline in the value of the Fund’s portfolio.

Interest Rate Risk is the risk that the value of the Fund’s investments will fall if interest rates rise. Interest rate risk generally is greater for funds that invest in fixed-income securities with relatively longer durations than for funds that invest in fixed-income securities with shorter durations.

Issuer Risk is the risk that the value of securities may decline due to a number of reasons relating to the issuer, such as management performance, financial leverage and reduced demand for the issuer’s goods and services.

Leverage Risk is the risk associated with securities or practices (e.g., borrowing and the use of certain derivatives) and investment in certain types of derivatives that multiply small index or market movements into larger changes in value. Use of derivative instruments may involve leverage. When a derivative is used as a hedge against an offsetting position that the Fund also holds, any loss generated by the derivative should be substantially offset by gains on the hedged instrument, and vice versa. To the extent that the Fund uses a derivative for purposes other than as a hedge, or if the Fund hedges imperfectly, the Fund is directly exposed to the risks of that derivative and any loss generated by the derivative will not be offset by a gain. Futures and forward currency contracts are derivatives and may be subject to this type of risk.

Liquidity Risk is the risk that the Fund may be unable to find a buyer for its investments when it seeks to sell them or to receive the price it expects. Liquidity issues may also make it difficult to value the Fund’s investments.

Management Risk is the risk that Loomis Sayles’ investment techniques will be unsuccessful and cause the Fund to incur losses.

Market Risk is the risk that the market value of a security may move up and down, sometimes rapidly and unpredictably, based upon a change in an issuer’s financial condition, as well as overall market and economic conditions.

Mortgage-Related and Asset-Backed Securities Risk is the risk that the securities may be prepaid and result in the reinvestment of the prepaid amounts in securities with lower yields than the prepaid obligations. Conversely, there is a risk that an unexpected rise in interest rates will extend the life of a mortgage-related or asset-backed security beyond the expected prepayment time, typically reducing the security’s value. The Fund may also incur a loss when there is a prepayment of securities that were purchased at a premium. It also includes risks associated with investing in the mortgages underlying the mortgage-backed securities. The market for mortgage-backed securities (and other asset-backed securities) has experienced high volatility and a lack of liquidity. As a result, the value of many of these securities has significantly declined. The Fund’s investments in other asset-backed securities are subject to risks similar to those associated with mortgage-related securities, as well as additional risks associated with the nature of the assets and the servicing of those assets.

REITs Risk is the risk that the value of the Fund’s investments in REITs will fall as a result of changes in underlying real estate values, rising interest rates, limited diversification of holdings, higher costs and prepayment risk associated with related mortgages, as well as other risks particular to investments in real estate.

The following bar chart and table give an indication of the risks of investing in the Fund by showing changes in the Fund’s performance from year to year and by showing how the Fund’s average annual returns for the one-year, five-year, ten-year and life-of-fund periods compare to those of a broad measure of market performance. The Fund’s past performance (before and after taxes) does not necessarily indicate how the Fund will perform in the future. Updated performance information is available online at www.loomissayles.com and/or by calling the Fund toll-free at 800-633-3330.

The Fund’s best quarter was 17.21%, (second quarter of 2009), and the Fund’s worst quarter was -13.00%, (third quarter of 2008).

The Fund’s Institutional Class shares total return year to date as of June 30, 2011 was 6.46% .


	One Year	Five Years	Ten Years	Life-of-Fund (5/16/91)
Institutional Class
Return Before Taxes	13.58%	8.03%	9.89%	10.43%
Return After Taxes on Distributions	11.25%	5.60%	7.26%	7.26%
Return After Taxes on Distributions and Sale of Fund Shares	8.76%	5.41%	6.96%	7.09%
Retail Class - Return Before Taxes	13.29%	7.72%	9.59%	10.15%
Admin Class - Return Before Taxes	12.95%	7.43%	9.31%	9.69%
Barclays Capital U.S. Government/Credit Bond Index	6.59%	5.56%	5.83%	6.83%

Total returns shown for the Fund reflect the results of the Loomis Sayles Bond Fund, a series of Loomis Sayles Funds II (the “Predecessor Fund”) whose assets and liabilities were reorganized into the Fund, a series of Loomis Sayles Funds I, on September 12, 2003. Prior to the inception of Retail Class shares (December 31, 1996) and Admin Class shares (January 2, 1998) of the Predecessor Fund, performance is that of the Institutional Class shares of the Predecessor Fund, restated to reflect the higher net expenses of the Retail Class and Admin Class shares of the Predecessor Fund.

After-tax returns are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after-tax returns depend on an investor’s tax situation and may differ from those shown. After-tax returns shown are not relevant to investors who hold their shares through tax-deferred arrangements, such as 401(k) plans, qualified plans, education savings accounts, such as 529 plans, or individual retirement accounts. The after-tax returns are shown for the Institutional Class of the Fund. After-tax returns for the other classes of the Fund will vary.

Matthew J. Eagan, CFA, Vice President of Loomis Sayles, has served as an associate portfolio manager of the Fund since February 2007.

Daniel J. Fuss, CFA, Vice Chairman, Director and Managing Partner of Loomis Sayles, has served as portfolio manager of the Fund since May 1991.

Kathleen C. Gaffney, CFA, Vice President of Loomis Sayles, has served as co-portfolio manager of the Fund since October 1997.

Elaine M. Stokes, Vice President of Loomis Sayles, has served as an associate portfolio manager of the Fund since February 2007.

The following chart shows the investment minimum for each class of shares of the Fund:


	Minimum Initial Investment	Minimum Subsequent Investment
Institutional Class	$100,000	$50
Retail Class	$2,500	$50
Admin Class	No Minimum	No Minimum

Admin Class shares are intended primarily for qualified retirement plans held in an omnibus fashion and are not available for purchase by individual investors.

The Fund’s shares are available for purchase (and are redeemable on any business day) through your financial adviser, through your broker-dealer, directly from the Fund by writing to the Fund at Loomis Sayles Funds, P.O. Box 219594, Kansas City, MO 64121-9594, by exchange, by wire, by internet at www.loomissayles.com, by telephone at 800-633-3330, through the Automated Clearing House system, or, in the case of redemptions, by the Systematic Withdrawal Plan.

Fund distributions are generally taxable to you as ordinary income or capital gain, except for distributions to retirement plans and other investors that qualify for tax-exempt treatment under U.S. federal income tax law generally.

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies may pay the intermediary for the sale of the Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.


				Institutional Class: LSBDX
				Retail Class: LSBRX
				Admin Class: LBFAX