Columbia Funds Series Trust

Summary Prospectus

June 1, 2019

Columbia Capital Allocation Moderate Aggressive Portfolio

Class		Ticker Symbol
A		NBIAX
Advisor (Class Adv)		CGBRX
C		NBICX
Institutional (Class Inst)		NBGPX
Institutional 2 (Class Inst2)		CLHRX
Institutional 3 (Class Inst3)		CPHNX
R		CLBRX
V		CGGTX

Beginning on January 1, 2021, as permitted by regulations adopted by the Securities and Exchange Commission, paper copies of the Fund's annual and semiannual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports. Instead, the reports will be made available on the Fund's website (columbiathreadneedleus.com/investor/), and each time a report is posted you will be notified by mail and provided with a website address to access the report.

If you have already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications from the Fund electronically at any time by contacting your financial intermediary (such as a broker-dealer or bank) or, for Fund shares held directly with the Fund, by calling 800.345.6611 or by enrolling in “eDelivery” by logging into your account at columbiathreadneedleus.com/investor/.

You may elect to receive all future reports in paper free of charge. If you invest through a financial intermediary, you can contact your financial intermediary to request that you continue receiving paper copies of your shareholder reports. If you invest directly with the Fund, you can call 800.345.6611 to let the Fund know you wish to continue receiving paper copies of your shareholder reports. Your election to receive paper reports will apply to all Columbia Funds held in your account if you invest through a financial intermediary or all Columbia Funds held with the fund complex if you invest directly with the Fund.

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, reports to shareholders, statement of additional information and other information about the Fund online at https://www.columbiathreadneedleus.com/resources/literature. If you hold your Fund shares through a financial intermediary (such as a broker-dealer or bank), you can get this information at no cost by contacting that financial intermediary. If you hold your Fund shares directly with the Fund, you can get this information at no cost by calling 800.345.6611 or by sending an email to serviceinquiries@columbiathreadneedle.com. This Summary Prospectus incorporates by reference the Fund’s prospectus, dated June 1, 2019, and current Statement of Additional Information.

As with all mutual funds, the Securities and Exchange Commission has not approved or disapproved these securities or passed upon the adequacy of this prospectus. Any representation to the contrary is a criminal offense.

Investment Objective

Columbia Capital Allocation Moderate Aggressive Portfolio (Moderate Aggressive Portfolio or the Fund) is designed for investors seeking the highest level of total return that is consistent with a moderate aggressive level of risk.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. An investor transacting in a class of Fund shares without any front-end sales charge, contingent deferred sales charge, or other asset-based fee for sales or distribution may be required to pay a commission to the financial intermediary for effecting such transactions. Such commission rates are set by the financial intermediary and are not reflected in the tables or the example below. You may qualify for sales charge discounts if you and members of your immediate family invest, or agree to invest in the future, at least $50,000 in certain classes of shares of eligible funds distributed by Columbia Management Investment Distributors, Inc. (the Distributor). More information is available about these and other sales charge discounts and waivers from your financial intermediary, and can be found in the Choosing a Share Class section beginning on page 72 of the Fund’s prospectus, in Appendix A to the prospectus beginning on page A-1 and in Appendix S to the Statement of Additional Information (SAI) under Sales Charge Waivers beginning on page S-1.

Shareholder Fees (fees paid directly from your investment)
	Classes A and V	Class C	Classes Adv, Inst, Inst2, Inst3 and R
Maximum sales charge (load) imposed on purchases (as a % of offering price)	5.75%	None	None
Maximum deferred sales charge (load) imposed on redemptions (as a % of the lower of the original purchase price or current net asset value)	1.00% ^(a)	1.00% ^(b)	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
	Class A	Class Adv	Class C	Class Inst	Class Inst2	Class Inst3	Class R	Class V
Management fees	0.11%	0.11%	0.11%	0.11%	0.11%	0.11%	0.11%	0.11%
Distribution and/or service (12b-1) fees	0.25%	0.00%	1.00%	0.00%	0.00%	0.00%	0.50%	0.00%
Other expenses	0.13%	0.13%	0.13%	0.13%	0.08%	0.03%	0.13%	0.38%
Acquired fund fees and expenses	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%	0.59%
Total annual Fund operating expenses^(c)	1.08%	0.83%	1.83%	0.83%	0.78%	0.73%	1.33%	1.08%

(a)	This charge is imposed on certain investments of between $1 million and $50 million redeemed within 18 months after purchase, as follows: 1.00% if redeemed within 12 months after purchase, and 0.50% if redeemed more than 12, but less than 18, months after purchase, with certain limited exceptions.
(b)	This charge applies to redemptions within 12 months after purchase, with certain limited exceptions.
(c)	"Total annual Fund operating expenses” include acquired fund fees and expenses (expenses the Fund incurs indirectly through its investments in other investment companies) and may be higher than the ratio of expenses to average net assets shown in the Financial Highlights section of this prospectus because the ratio of expenses to average net assets does not include acquired fund fees and expenses.

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Example

The following 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 illustrates the hypothetical expenses that you would incur over the time periods indicated, and assumes that:

■	you invest $10,000 in the applicable class of Fund shares for the periods indicated,
■	your investment has a 5% return each year, and
■	the Fund’s total annual operating expenses remain the same as shown in the Annual Fund Operating Expenses table above.

Although your actual costs may be higher or lower, based on the assumptions listed above, your costs would be:

	1 year	3 years	5 years	10 years
Class A (whether or not shares are redeemed)	$679	$899	$1,136	$1,816
Class Adv (whether or not shares are redeemed)	$ 85	$265	$ 460	$1,025
Class C (assuming redemption of all shares at the end of the period)	$286	$576	$ 990	$2,148
Class C (assuming no redemption of shares)	$186	$576	$ 990	$2,148
Class Inst (whether or not shares are redeemed)	$ 85	$265	$ 460	$1,025
Class Inst2 (whether or not shares are redeemed)	$ 80	$249	$ 433	$ 966
Class Inst3 (whether or not shares are redeemed)	$ 75	$233	$ 406	$ 906
Class R (whether or not shares are redeemed)	$135	$421	$ 729	$1,601
Class V (whether or not shares are redeemed)	$679	$899	$1,136	$1,816

Portfolio Turnover

The Fund and underlying funds (including exchange-traded funds (ETFs)) may pay transaction costs, such as commissions, when they buy and sell securities (or “turn over” their portfolios). The Fund will indirectly bear the expenses associated with portfolio turnover of the underlying funds. A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when 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 the most recent fiscal year, the Fund’s portfolio turnover rate was 18% of the average value of its portfolio.

Principal Investment Strategies

The Fund is primarily managed as a fund that invests in other funds (i.e., a “fund-of-funds”) that seeks to achieve its investment objective by investing under normal circumstances in a combination of underlying funds for which Columbia Management Investment Advisers, LLC (the Investment Manager) or an affiliate serves as investment adviser or principal underwriter (the affiliated underlying funds). The Fund may also invest up to 20% of its net assets in other funds, including third party advised (unaffiliated) funds and exchange-traded funds (ETFs) (collectively with the affiliated underlying funds, the Underlying Funds), equity securities, fixed income securities (including treasury inflation protected securities (TIPS)) and derivative instruments (the 20% Sleeve). The Fund’s derivative investments may include forward contracts (including forward foreign currency contracts), futures (including currency, equity, index, interest rate, and other bond futures) and options. Derivative positions may be established to seek incremental earnings, hedge existing positions, increase market or credit exposure, increase investment flexibility (including using the derivative position as a substitute for the purchase or sale of the underlying security, currency or other instrument) and/or to change the effective duration of the Fund’s portfolio. Collectively, these investments (including through investments in derivatives) provide the Fund with exposure to equity, fixed income, and cash/cash equivalent asset classes. The Fund may also pursue alternative investment strategies (alternative strategies), including those that seek investment returns uncorrelated to the broad equity and fixed income markets, as well as those providing exposure to other markets, including but not limited to absolute (positive) return strategies.

The Fund may invest in Underlying Funds categorized as “equity”, “fixed income”, “cash/cash equivalents”, and “alternative strategies”, which may represent indirect investments in various sectors, asset classes, strategies and markets. Under normal circumstances, the Fund emphasizes investments in Underlying Funds categorized as equity, which can include those that invest in equity securities representing different investment styles (e.g., growth, value and core/blend), market capitalizations (large-, mid- and small-cap), geographic focus (domestic and international, including emerging markets) and sector focus (e.g., real estate, technology, infrastructure and natural resources). The Fund may also invest in Underlying Funds categorized as fixed income, which can include those investing in TIPs, U.S. treasury bonds and notes, mortgage-backed and asset-backed securities, investment grade corporate bonds, high yield bonds (junk bonds), high yield loans and international bonds (including those of issuers in developed and emerging markets), which may have varying interest rates, terms, duration and credit exposure. The Underlying Funds

Columbia Capital Allocation Moderate Aggressive Portfolio

categorized as alternative strategies include those that employ a variety of investment strategies, techniques and practices, generally intended to have a low correlation to the performance of the broad equity and fixed income markets over a complete market cycle including but not limited to absolute (positive) return strategies. Subject to the 20% Sleeve limitation described above, the Fund may also invest directly in equity securities, fixed income securities and derivative instruments, including forward foreign currency contracts and futures (including currency, equity, fixed income, index and interest rate futures). By investing in a combination of Underlying Funds and other securities described in the 20% Sleeve, the Fund seeks to minimize the risks typically associated with investing in a traditional mutual fund.

Under normal market circumstances, the Fund may invest, directly or indirectly, in each of equity, fixed income and cash/cash equivalent asset classes and alternative strategies (each, an asset class category and collectively, the asset class categories) within the following target asset allocation ranges (includes investments in Underlying Funds and the other securities described in the 20% Sleeve):

Asset Class Exposures
	Equity	Fixed Income	Cash/Cash Equivalents	Alternatives
Moderate Aggressive Portfolio	20–85%*	15–60%*	0–40%*	0–40%*

As a percent of Fund net assets. Ranges include the net notional amounts of a Fund’s direct investments in derivative instruments. Market appreciation or depreciation may cause a Fund to be temporarily outside the ranges identified in the table. The Investment Manager may modify the target allocation ranges only with the approval of a Fund’s Board of Trustees (the Board).

The Fund may be most appropriate for investors with an intermediate-to-long term investment horizon.

Principal Risks

An investment in the Fund involves risks, including Fund-of-Funds Risk, as well as specific risks related to the underlying funds in which it invests that in the aggregate are principal risks to the Fund, including among others, those described below. Descriptions of these and other principal risks of investing in the Fund are provided below. More information about underlying funds, including their principal risks, is available in their prospectuses, which are incorporated by reference into this prospectus. A description of the principal risks associated with investment in these underlying funds is included in Appendix C. This prospectus is not an offer for any of the underlying funds. There is no assurance that the Fund will achieve its investment objective and you may lose money. The value of the Fund’s holdings may decline, and the Fund’s net asset value (NAV) and share price may go down. An investment in the Fund is not a bank deposit and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.

Allocation Risk. Because the Fund uses an asset allocation strategy in pursuit of its investment objective, there is a risk that the Fund's allocation among asset classes, investments, managers, strategies and/or investment styles will cause the Fund's shares to lose value or cause the Fund to underperform other funds with similar investment objectives and/or strategies, or that the investments themselves will not produce the returns expected.

Alternative Strategies Investment Risk. An investment in alternative investment strategies (Alternative Strategies), whether through direct investment or through one or more underlying funds that use Alternative Strategies, involves risks, which may be significant. Alternative Strategies may include strategies, instruments or other assets, such as derivatives, that seek investment returns uncorrelated with the broad equity and fixed income/debt markets, as well as those providing exposure to other markets (such as commodity markets), including but not limited to absolute (positive) return strategies. Alternative Strategies may fail to achieve their desired performance, market or other exposure, or their returns (or lack thereof) may be more correlated with the broad equity and/or fixed income/debt markets than was anticipated, and the Fund may lose money. Some Alternative Strategies may be considered speculative.

Counterparty Risk. Counterparty risk is the risk that a counterparty to a transaction in a financial instrument held by the Fund or by a special purpose or structured vehicle invested in by the Fund may become insolvent or otherwise fail to perform its obligations. As a result, the Fund may obtain no or limited recovery of its investment, and any recovery may be significantly delayed.

Credit Risk. Credit risk is the risk that the value of loans or other debt instruments may decline if the issuer thereof defaults or otherwise becomes unable or unwilling, or is perceived to be unable or unwilling, to honor its financial obligations, such as making payments to the Fund when due. Rating agencies assign credit ratings to certain debt instruments to indicate their credit risk. Unless otherwise provided in the Fund’s Principal Investment Strategies, investment grade debt instruments are those rated at or above BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. Conversely, below investment grade (commonly called “high-yield” or “junk”) debt instruments are

3	Columbia Capital Allocation Moderate Aggressive Portfolio

those rated below BBB- by S&P Global Ratings, or equivalently rated by Moody’s Investors Service, Inc. or Fitch, Inc., or, if unrated, determined by the management team to be of comparable quality. A rating downgrade by such agencies can negatively impact the value of such instruments. Lower quality or unrated instruments held by the Fund may present increased credit risk as compared to higher-rated instruments. Non-investment grade debt instruments may be subject to greater price fluctuations and are more likely to experience a default than investment grade debt instruments and therefore may expose the Fund to increased credit risk. If the Fund purchases unrated instruments, or if the ratings of instruments held by the Fund are lowered after purchase, the Fund will depend on analysis of credit risk more heavily than usual.

Derivatives Risk. Derivatives may involve significant risks. Derivatives are financial instruments with a value in relation to, or derived from, the value of an underlying asset(s) or other reference, such as an index, rate or other economic indicator (each an underlying reference). Derivatives may include those that are privately placed or otherwise exempt from SEC registration, including certain Rule 144A eligible securities. Derivatives could result in Fund losses if the underlying reference does not perform as anticipated. Use of derivatives is a highly specialized activity that can involve investment techniques, risks, and tax planning different from those associated with more traditional investment instruments. The Fund’s derivatives strategy may not be successful and use of certain derivatives could result in substantial, potentially unlimited, losses to the Fund regardless of the Fund’s actual investment. A relatively small movement in the price, rate or other economic indicator associated with the underlying reference may result in substantial loss for the Fund. Derivatives may be more volatile than other types of investments. The value of derivatives may be influenced by a variety of factors, including national and international political and economic developments. Potential changes to the regulation of the derivatives markets may make derivatives more costly, may limit the market for derivatives, or may otherwise adversely affect the value or performance of derivatives. Derivatives can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk, foreign currency risk and interest rate risk, while exposing the Fund to correlation risk, counterparty risk, hedging risk, inflation risk, leverage risk, liquidity risk, pricing risk and volatility risk.

Derivatives Risk – Forward Contracts Risk. A forward contract is an over-the-counter derivative transaction between two parties to buy or sell a specified amount of an underlying reference at a specified price (or rate) on a specified date in the future. Forward contracts are negotiated on an individual basis and are not standardized or traded on exchanges. The market for forward contracts is substantially unregulated and can experience lengthy periods of illiquidity, unusually high trading volume and other negative impacts, such as political intervention, which may result in volatility or disruptions in such markets. A relatively small price movement in a forward contract may result in substantial losses to the Fund, exceeding the amount of the margin paid. Forward contracts can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk, foreign currency risk and interest rate risk, while also exposing the Fund to correlation risk, counterparty risk, hedging risk, inflation risk, leverage risk, liquidity risk, pricing risk and volatility risk.

Derivatives Risk – Futures Contracts Risk. A futures contract is an exchange-traded derivative transaction between two parties in which a buyer (holding the “long” position) agrees to pay a fixed price (or rate) at a specified future date for delivery of an underlying reference from a seller (holding the “short” position). The seller hopes that the market price on the delivery date is less than the agreed upon price, while the buyer hopes for the contrary. Certain futures contract markets are highly volatile, and futures contracts may be illiquid. Futures exchanges may limit fluctuations in futures contract prices by imposing a maximum permissible daily price movement. The Fund may be disadvantaged if it is prohibited from executing a trade outside the daily permissible price movement. At or prior to maturity of a futures contract, the Fund may enter into an offsetting contract and may incur a loss to the extent there has been adverse movement in futures contract prices. The liquidity of the futures markets depends on participants entering into offsetting transactions rather than making or taking delivery. To the extent participants make or take delivery, liquidity in the futures market could be reduced. Because of the low margin deposits normally required in futures trading, it is possible that the Fund may employ a high degree of leverage in the portfolio. As a result, a relatively small price movement in a futures contract may result in substantial losses to the Fund, exceeding the amount of the margin paid. For certain types of futures contracts, losses are potentially unlimited. Futures markets are highly volatile and the use of futures may increase the volatility of the Fund’s NAV. Futures contracts executed (if any) on foreign exchanges may not provide the same protection as U.S. exchanges. Futures contracts can increase the Fund’s risk exposure to underlying references and their attendant risks, such as credit risk, market risk, foreign currency risk and interest rate risk, while also exposing the Fund to correlation risk, counterparty risk, hedging risk, inflation risk, leverage risk, liquidity risk, pricing risk and volatility risk.

Derivatives Risk – Options Risk. Options are derivatives that give the purchaser the option to buy (call) or sell (put) an underlying reference from or to a counterparty at a specified price (the strike price) on or before an expiration date. By investing in options, the Fund is exposed to the risk that it may be required to buy or sell the underlying reference at a disadvantageous price on or before the expiration date. Options may involve economic leverage, which

Columbia Capital Allocation Moderate Aggressive Portfolio

could result in greater volatility in price movement. The Fund's losses could be significant, and are potentially unlimited for certain types of options. Options may be traded on a securities exchange or in the over-the-counter market. At or prior to maturity of an options contract, the Fund may enter into an offsetting contract and may incur a loss to the extent there has been adverse movement in options prices. Options can increase the Fund’s risk exposure to underlying references and their attendant risks such as credit risk, market risk, foreign currency risk and interest rate risk, while also exposing the Fund to correlation risk, counterparty risk, hedging risk, leverage risk, liquidity risk, pricing risk and volatility risk.

Exchange-Traded Fund (ETF) Risk. Investments in ETFs have unique characteristics, including, but not limited to, the expense structure and additional expenses associated with investing in ETFs. ETFs are subject to, among other risks, tracking risk and passive and, in some cases, active investment risk. In addition, shareholders bear both their proportionate share of the Fund’s expenses, and indirectly the ETF’s expenses, incurred through the Fund’s ownership of the ETF. Due to the expenses and costs of an underlying ETF being shared by its investors, redemptions by other investors in the ETF could result in decreased economies of scale and increased operating expenses for such ETF. The ETFs may not achieve their investment objective. The Fund, through its investment in ETFs, may not achieve its investment objective.

Foreign Securities Risk. Investments in or exposure to foreign securities involve certain risks not associated with investments in or exposure to securities of U.S. companies. Foreign securities subject the Fund to the risks associated with investing in the particular country of an issuer, including political, regulatory, economic, social, diplomatic and other conditions or events (including, for example, military confrontations, war and terrorism), occurring in the country or region, as well as risks associated with less developed custody and settlement practices. Foreign securities may be more volatile and less liquid than securities of U.S. companies, and are subject to the risks associated with potential imposition of economic and other sanctions against a particular foreign country, its nationals or industries or businesses within the country. In addition, foreign governments may impose withholding or other taxes on the Fund’s income, capital gains or proceeds from the disposition of foreign securities, which could reduce the Fund’s return on such securities.

Fund-of-Funds Risk. Determinations regarding asset classes or underlying funds and the Fund’s allocations thereto may not successfully achieve the Fund’s investment objective, in whole or in part. The ability of the Fund to realize its investment objective will depend, in large part, on the extent to which the underlying funds realize their investment objective. There is no guarantee that the underlying funds will achieve their respective investment objectives. The Fund is exposed to the same risks as the underlying funds in direct proportion to the allocation of its assets among the underlying funds. Therefore, to the extent that the Fund invests significantly in a particular underlying fund, the Fund’s performance would be significantly impacted by the performance of such underlying fund. Generally, by investing in a combination of underlying funds, the Fund has exposure to the risks of many areas of the market. By concentrating its investments in relatively few underlying funds, the Fund may have more concentrated market exposures, subjecting the Fund to greater risk of loss should those markets decline or fail to rise. The performance of underlying funds could be adversely affected if other entities that invest in the same underlying funds make relatively large investments or redemptions in such underlying funds. The Fund, and its shareholders, indirectly bear a portion of the expenses of any funds in which the Fund invests. Because the expenses and costs of each underlying fund are shared by its investors, redemptions by other investors in an underlying fund could result in decreased economies of scale and increased operating expenses for such fund. The Investment Manager has a conflict of interest in selecting affiliated underlying funds over unaffiliated underlying funds because it receives management fees from affiliated funds, and it has a conflict in selecting affiliated underlying funds, because the fees paid to it by certain affiliated underlying funds are higher than the fees paid by other affiliated underlying funds. Also, to the extent that the Fund is constrained/restricted from investing (or investing further) in a particular underlying fund for one or more reasons (e.g., underlying fund capacity constraints or regulatory restrictions) or if the Fund chooses to sell its investment in an underlying fund because of poor investment performance or for other reasons, the Fund may have to invest in another underlying fund(s), including less desirable funds – from a strategy or investment performance standpoint – which could have a negative impact on Fund performance. In addition, Fund performance could be negatively impacted if the Investment Manager is unable to identify an appropriate alternate underlying fund(s) in a timely manner or at all.

Growth Securities Risk. Growth securities typically trade at a higher multiple of earnings than other types of equity securities. Accordingly, the market values of growth securities may never reach their expected market value and may decline in price. In addition, growth securities, at times, may not perform as well as value securities or the stock market in general, and may be out of favor with investors for varying periods of time.

5	Columbia Capital Allocation Moderate Aggressive Portfolio

Inflation-Protected Securities Risk. Inflation-protected debt securities tend to react to changes in real interest rates (i.e., nominal interest rates minus the expected impact of inflation). In general, the price of such securities falls when real interest rates rise, and rises when real interest rates fall. Interest payments on these securities will vary and may be more volatile than interest paid on ordinary bonds. In periods of deflation, the Fund may have no income at all from such investments.

Interest Rate Risk. Interest rate risk is the risk of losses attributable to changes in interest rates. In general, if prevailing interest rates rise, the values of debt instruments tend to fall, and if interest rates fall, the values of debt instruments tend to rise. Changes in the value of a debt instrument usually will not affect the amount of income the Fund receives from it but will generally affect the value of your investment in the Fund. Changes in interest rates may also affect the liquidity of the Fund’s investments in debt instruments. In general, the longer the maturity or duration of a debt instrument, the greater its sensitivity to changes in interest rates. Interest rate declines also may increase prepayments of debt obligations, which, in turn, would increase prepayment risk. Similarly, a period of rising interest rates may negatively impact the Fund’s performance. Actions by governments and central banking authorities can result in increases in interest rates. Such actions may negatively affect the value of debt instruments held by the Fund, resulting in a negative impact on the Fund's performance and NAV. Any interest rate increases could cause the value of the Fund’s investments in debt instruments to decrease. Rising interest rates may prompt redemptions from the Fund, which may force the Fund to sell investments at a time when it is not advantageous to do so, which could result in losses.

Issuer Risk. An issuer in which the Fund invests or to which it has exposure may perform poorly, and the value of its securities may therefore decline, which may negatively affect the Fund’s performance. Underperformance may be caused by poor management decisions, competitive pressures, breakthroughs in technology, reliance on suppliers, labor problems or shortages, corporate restructurings, fraudulent disclosures, natural disasters or other events, conditions or factors.

High-Yield Investments Risk. Securities and other debt instruments held by the Fund that are rated below investment grade (commonly called “high-yield” or “junk” bonds) and unrated debt instruments of comparable quality expose the Fund to a greater risk of loss of principal and income than a fund that invests solely or primarily in investment grade debt instruments. In addition, these investments have greater price fluctuations, are less liquid and are more likely to experience a default than higher-rated debt instruments. High-yield debt instruments are considered to be predominantly speculative with respect to the issuer’s capacity to pay interest and repay principal.

Market Risk. The market values of securities or other investments that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. An investment in the Fund could lose money over short or long periods.

Money Market Fund Investment Risk. An investment in a money market fund is not a bank deposit and is not insured or guaranteed by any bank, the FDIC or any other government agency. Certain money market funds float their NAV while others seek to preserve the value of investments at a stable NAV (typically, $1.00 per share). An investment in a money market fund, even an investment in a fund seeking to maintain a stable NAV per share, is not guaranteed and it is possible for the Fund to lose money by investing in these and other types of money market funds. If the liquidity of a money market fund’s portfolio deteriorates below certain levels, the money market fund may suspend redemptions (i.e., impose a redemption gate) and thereby prevent the Fund from selling its investment in the money market fund or impose a fee of up to 2% on amounts the Fund redeems from the money market fund (i.e., impose a liquidity fee). These measures may result in an investment loss or prohibit the Fund from redeeming shares when the Investment Manager would otherwise redeem shares. In addition to the fees and expenses that the Fund directly bears, the Fund indirectly bears the fees and expenses of any money market funds in which it invests, including affiliated money market funds. By investing in a money market fund, the Fund will be exposed to the investment risks of the money market fund in direct proportion to such investment. To the extent the Fund invests in instruments such as derivatives, the Fund may hold investments, which may be significant, in money market fund shares to cover its obligations resulting from the Fund’s investments in derivatives. Money market funds and the securities they invest in are subject to comprehensive regulations. The enactment of new legislation or regulations, as well as changes in interpretation and enforcement of current laws, may affect the manner of operation, performance and/or yield of money market funds.

Prepayment and Extension Risk. Prepayment and extension risk is the risk that a bond or other security or investment might, in the case of prepayment risk, be called or otherwise converted, prepaid or redeemed before maturity and, in the case of extension risk, that the investment might not be called as expected. In the case of prepayment risk, if the investment is converted, prepaid or redeemed before maturity, the portfolio managers may not be able to invest the proceeds in other investments providing as high a level of income, resulting in a reduced yield to the Fund. In the case of mortgage- or other asset-backed securities, as interest rates decrease or spreads narrow, the likelihood of prepayment increases. Conversely, extension risk is the risk that an unexpected rise in

Columbia Capital Allocation Moderate Aggressive Portfolio

interest rates will extend the life of a mortgage- or other asset-backed security beyond the prepayment time. If the Fund’s investments are locked in at a lower interest rate for a longer period of time, the portfolio managers may be unable to capitalize on securities with higher interest rates or wider spreads.

Value Securities Risk. Value securities are securities of companies that may have experienced, for example, adverse business, industry or other developments or may be subject to special risks that have caused the securities to be out of favor and, in turn, potentially undervalued. The market value of a portfolio security may not meet portfolio management’s perceived value assessment of that security, or may decline in price, even though portfolio management believes the securities are already undervalued. There is also a risk that it may take longer than expected for the value of these investments to rise to portfolio management’s perceived value. In addition, value securities, at times, may not perform as well as growth securities or the stock market in general, and may be out of favor with investors for varying periods of time.

Performance Information

The following bar chart and table show you how the Fund has performed in the past, and can help you understand the risks of investing in the Fund. The bar chart shows how the Fund’s Class A share performance (without sales charges) has varied for each full calendar year shown. If the sales charges were reflected, returns shown would be lower. The table below the bar chart compares the Fund’s returns (after applicable sales charges shown in the Shareholder Fees table in this prospectus) for the periods shown with a blended benchmark that is intended to provide a measure of the Fund's performance given its investment strategy, as well as two additional measures of performance for markets in which the Fund may invest.

The performance of one or more share classes shown in the table below begins before the indicated inception date for such share class. The returns shown for each such share class include the returns of the Fund’s Class A shares (without applicable sales charges and adjusted to reflect the higher class-related operating expenses of such share classes, where applicable) for periods prior to its inception date. Share classes with expenses that are higher than Class A shares will have performance that is lower than Class A shares (without applicable sales charges). Except for differences in annual returns resulting from differences in expenses and sales charges (where applicable), the share classes of the Fund would have substantially similar annual returns because all share classes of the Fund invest in the same portfolio of securities.

The after-tax returns shown in the Average Annual Total Returns table below are calculated using the highest historical individual U.S. federal marginal income tax rates in effect during the period indicated in the table and do not reflect the impact of state, local or foreign taxes. Your actual after-tax returns will depend on your personal tax situation and may differ from those shown in the table. In addition, the after-tax returns shown in the table do not apply to shares held in tax-advantaged accounts such as 401(k) plans or Individual Retirement Accounts (IRAs). The after-tax returns are shown only for Class A shares and will vary for other share classes. Returns after taxes on distributions and sale of Fund shares are higher than before-tax returns for certain periods shown because they reflect the tax benefit of capital losses realized on the redemption of Fund shares.

The Fund’s past performance (before and after taxes) is no guarantee of how the Fund will perform in the future. Updated performance information can be obtained by calling toll-free 800.345.6611 or visiting columbiathreadneedleus.com.

Year by Year Total Return (%) as of December 31 Each Year*	Best and Worst Quarterly Returns During the Period Shown in the Bar Chart
	_Best	_{2nd Quarter 2009}	_16.41%
	_Worst	_{3rd Quarter 2011}	_-11.49%

*	Year to Date return as of March 31, 2019: 10.17%

7	Columbia Capital Allocation Moderate Aggressive Portfolio

Average Annual Total Returns After Applicable Sales Charges (for periods ended December 31, 2018)

	Share Class Inception Date	1 Year	5 Years	10 Years
Class A	10/15/1996
returns before taxes		-13.05%	2.98%	8.59%
returns after taxes on distributions		-15.15%	0.85%	7.10%
returns after taxes on distributions and sale of Fund shares		-6.58%	2.02%	6.75%
Class Adv returns before taxes	11/08/2012	-7.46%	4.46%	9.41%
Class C returns before taxes	10/15/1996	-9.29%	3.42%	8.43%
Class Inst returns before taxes	10/15/1996	-7.54%	4.45%	9.50%
Class Inst2 returns before taxes	11/08/2012	-7.42%	4.56%	9.47%
Class Inst3 returns before taxes	06/13/2013	-7.46%	4.59%	9.47%
Class R returns before taxes	01/23/2006	-8.00%	3.95%	8.97%
Class V returns before taxes	03/07/2011	-13.05%	2.97%	8.56%
Blended Benchmark (consisting of 49% Russell 3000 Index, 28.5% Bloomberg Barclays U.S. Aggregate Bond Index, 12% MSCI EAFE Index (Net), 6.5% Bloomberg Barclays U.S. Corporate High-Yield Index and 4% MSCI Emerging Markets Index (Net)) (reflects reinvested dividends net of withholding taxes on the MSCI EAFE Index and the MSCI Emerging Markets Index portion of the Blended Benchmark, and for all indexes reflects no deductions for fees, expenses or other taxes)		-4.75%	5.13%	9.48%
Russell 3000 Index (reflects no deductions for fees, expenses or taxes)		-5.24%	7.91%	13.18%
Bloomberg Barclays U.S. Aggregate Bond Index (reflects no deductions for fees, expenses or taxes)		0.01%	2.52%	3.48%

Fund Management

Investment Manager: Columbia Management Investment Advisers, LLC

Portfolio Manager	Title	Role with Fund	Managed Fund Since
Anwiti Bahuguna, Ph.D.	Senior Portfolio Manager and Head of Multi Asset Strategy	Lead Portfolio Manager	2009
Dan Boncarosky, CFA	Portfolio Manager	Portfolio Manager	2017

Purchase and Sale of Fund Shares

You may purchase or redeem shares of the Fund on any business day by contacting the Fund in the ways described below:

Online		Regular Mail		Express Mail		By Telephone
columbiathreadneedleus.com/investor/		Columbia Management Investment Services Corp. P.O. Box 219104 Kansas City, MO 64121-9104		Columbia Management Investment Services Corp. c/o DST Asset Manager Solutions, Inc. 430 W 7^th Street, Suite 219104 Kansas City, MO 64105-1407		800.422.3737

You may purchase shares and receive redemption proceeds by electronic funds transfer, by check or by wire. If you maintain your account with a broker-dealer or other financial intermediary, you must contact that financial intermediary to buy, sell or exchange shares of the Fund through your account with the intermediary.

The minimum initial investment amounts for the share classes offered by the Fund are shown below:

Minimum Initial Investment

Class	Category of eligible account	For accounts other than systematic investment plan accounts	For systematic investment plan accounts
Classes A, C & V^(a)	All accounts other than IRAs	$2,000	$100
Classes A, C & V^(a)	IRAs	$1,000	$100
Classes Adv & Inst	All eligible accounts	$0, $1,000 or $2,000 depending upon the category of eligible investor	$100

Columbia Capital Allocation Moderate Aggressive Portfolio

Class	Category of eligible account	For accounts other than systematic investment plan accounts	For systematic investment plan accounts
Classes Inst2 & R	All eligible accounts	None	N/A
Class Inst3	All eligible accounts	$0, $1,000, $2,000 or $1 million depending upon the category of eligible investor	$100 (for certain eligible investors)

(a)	Class V shares are generally closed to new investors.

More information about these minimums can be found in the Buying, Selling and Exchanging Shares - Buying Shares section of the prospectus. There is no minimum additional investment for any share class.

Tax Information

The Fund normally distributes net investment income and net realized capital gains, if any, to shareholders. These distributions are generally taxable to you as ordinary income or capital gains, unless you are investing through a tax-advantaged account, such as a 401(k) plan or an IRA. The use of a fund-of-funds structure could affect the timing, amount and character of distributions to you and therefore may increase the amount of taxes payable by you. If you are investing through a tax-advantaged account, you may be taxed upon withdrawals from that account.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase the Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund and its related companies — including Columbia Management Investment Advisers, LLC (the Investment Manager), Columbia Management Investment Distributors, Inc. (the Distributor) and Columbia Management Investment Services Corp. (the Transfer Agent) — may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your financial advisor to recommend the Fund over another investment. Ask your financial advisor or visit your financial intermediary’s website for more information.

9	Columbia Capital Allocation Moderate Aggressive Portfolio

Columbia Threadneedle Investments is the global brand name of the Columbia and Threadneedle group of companies.

columbiathreadneedleus.com

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