(Columbia Acorn Select)

Investment Objective

The Fund seeks long-term capital appreciation.

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. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $50,000 in certain classes of shares of eligible Columbia Funds. More information about these and other discounts is available from your financial advisor, in the Choosing a Share Class section beginning on page 21 of this prospectus and in Appendix S to the Statement of Additional Information under Sales Charge Waivers beginning on page S-1. The Fund no longer accepts investments from new or existing investors in Class B shares. Class I shares are generally available only to other Columbia Funds.

Shareholder Fees (fees paid directly from your investment)

Shareholder Fees (Columbia Acorn Select)	Class A Shares		Class B Shares		Class C Shares		Class I Shares	Class R4 Shares	Class R5 Shares	Class Y Shares	Class Z Shares
Maximum sales charge (load) imposed on purchases, as a % of offering price	5.75%		none		none		none	none	none	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%	[1]	5.00%	[2]	1.00%	[3]	none	none	none	none	none

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Annual Fund Operating Expenses (Columbia Acorn Select)		Class A Shares	Class B Shares	Class C Shares	Class I Shares	Class R4 Shares	Class R5 Shares	Class Y Shares	Class Z Shares
Management fees		0.83%	0.83%	0.83%	0.83%	0.83%	0.83%	0.83%	0.83%
Distribution and/or service (Rule 12b-1) fees		0.25%	0.75%	1.00%	none	none	none	none	none
Other expenses	[1]	0.27%	0.37%	0.25%	0.12%	0.32%	0.17%	0.12%	0.24%
Total annual Fund operating expenses		1.35%	1.95%	2.08%	0.95%	1.15%	1.00%	0.95%	1.07%

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 Class A, Class B, Class C, Class I, Class R4, Class R5, Class Y or Class Z shares of the Fund 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 table above.

Based on the assumptions listed above, your costs would be:

Expense Example (Columbia Acorn Select) (USD $)	1 Year	3 Years	5 Years	10 Years
Class A Shares	705	978	1,272	2,105
Class B Shares	698	912	1,252	2,120
Class C Shares	311	652	1,119	2,410
Class I Shares	97	303	525	1,166
Class R4 Shares	117	365	633	1,398
Class R5 Shares	102	318	552	1,225
Class Y Shares	97	303	525	1,166
Class Z Shares	109	340	590	1,306

Expense Example, No Redemption (Columbia Acorn Select) (USD $)	1 Year	3 Years	5 Years	10 Years
Class B Shares	198	612	1,052	2,120
Class C Shares	211	652	1,119	2,410

Remember this is an example only. Your actual costs may be higher or lower.

Portfolio Turnover

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 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 15% of the average value of its portfolio.

Principal Investment Strategies

Under normal circumstances, the Fund invests a majority of its net assets in the common stock of companies with market capitalizations under $20 billion at the time of investment. However, if the Fund's investments in such companies represent less than a majority of its net assets, the Fund may continue to hold and to make additional investments in an existing company in its portfolio even if that company's capitalization has grown to exceed $20 billion. Except as noted above, under normal circumstances, the Fund may invest in other companies with market capitalizations above $20 billion, provided that immediately after that investment a majority of its net assets would be invested in companies with market capitalizations under $20 billion.

Columbia Wanger Asset Management, LLC, the Fund's investment adviser (the Investment Manager), believes that stocks of companies with market capitalizations under $20 billion, which generally are not as well known by financial analysts as larger companies, may offer higher return potential than stocks of larger companies.

The Fund invests the majority of its assets in U.S. companies, but also may invest up to 33% of its total assets in foreign companies in developed markets (for example, Japan, Canada and the United Kingdom) and in emerging markets (for example, China, India and Colombia).

The Fund takes advantage of the Investment Manager's research and stock-picking capabilities to invest in a limited number of companies (generally between 30-60), offering the potential to provide above-average growth over time.

The Investment Manager typically seeks companies with:

• A strong business franchise that offers growth potential.

• Products and services that give the company a competitive advantage.

• A stock price the Investment Manager believes is reasonable relative to the assets and earning power of the company.

The Fund may also invest in companies that the Investment Manager believes have good operational fundamentals but that the Investment Manager believes are undervalued due to negative investor sentiment related to company-specific or market-related conditions. Investments in turnaround and development stage companies may also be made when the Investment Manager believes potential returns outweigh risks of losses.

The Investment Manager may sell a portfolio holding if the security reaches the Investment Manager's price target, if the company has a deterioration of fundamentals, such as failing to meet key operating benchmarks, or if the Investment Manager believes other securities are more attractive. The Investment Manager also may sell a portfolio holding to fund redemptions.

Principal Risks

• Investment Strategy Risk – The Fund's manager uses the principal investment strategies and other investment strategies to seek to achieve the Fund's investment objective. There is no assurance that the Fund will achieve its investment objective. Investment decisions may not produce the expected returns, may cause the Fund's shares to lose value or may cause the Fund to underperform other funds with similar investment objectives.

• Market Risk – Market risk refers to the possibility that the market values of securities that the Fund holds will fall, sometimes rapidly or unpredictably, or fail to rise. Security values may fall because of factors affecting individual companies, industries or sectors, or the markets as a whole, reducing the value of an investment in the Fund. Accordingly, an investment in the Fund could lose money over short or even long periods, or fail to increase in value. The market values of the securities the Fund holds also can be affected by changes or perceived changes in U.S. or foreign economies and financial markets, and the liquidity of these securities, among other factors. In general, equity securities tend to have greater price volatility than debt securities.

• Smaller Company Securities Risk – Securities of small- or mid-capitalization companies ("smaller companies") can, in certain circumstances, have a higher potential for gains than securities of large-capitalization companies but may also have more risk. For example, smaller companies may be more vulnerable to market downturns and adverse business or economic events than larger, more established companies because they may have more limited financial resources and business operations. These companies are also more likely than large-capitalization companies ("larger companies") to have more limited product lines and operating histories and to depend on smaller management teams. Their securities may trade less frequently and in smaller volumes and may be less liquid and fluctuate more sharply in value than securities of larger companies. In cases where the Fund takes significant positions in smaller companies with limited trading volumes, the liquidation of those positions, particularly in a distressed market, could be prolonged and result in investment losses. In addition, some smaller companies may not be widely followed by the investment community, which can lower the demand for their stocks.

• Sector Risk – At times, the Fund may have a significant portion of its assets invested in securities of companies conducting business in a broadly related group of industries within an economic sector. Companies in the same economic sector may be similarly affected by economic or market events, making the Fund more vulnerable to unfavorable developments in that economic sector than funds that invest more broadly.

• Foreign Securities Risk – Foreign securities are subject to special risks as compared to securities of U.S. issuers. For example, foreign markets can be extremely volatile. Fluctuations in currency exchange rates may impact the value of foreign securities denominated in foreign currencies, or in U.S. dollars, without a change in the intrinsic value of those securities. Foreign securities may be less liquid than domestic securities so that the Fund may, at times, be unable to sell foreign securities at desirable times or prices. Brokerage commissions, custodial fees and other fees are also generally higher for foreign securities. The Fund may have limited or no legal recourse in the event of default with respect to certain foreign securities, including those issued by foreign governments. Foreign governments may impose potentially confiscatory withholding or other taxes, which could reduce the amount of income and capital gains available to distribute to shareholders. There is generally less publicly available information about foreign companies. Investments in foreign companies may be adversely affected by the impact of political, social or diplomatic events, possible imposition of currency exchange controls or possible seizure, expropriation or nationalization of a company or its assets resulting in a partial or total loss of an investment in such foreign companies. Accounting, auditing and financial reporting standards may also be less comprehensive and stringent than those applicable to domestic companies.

  Operational and Settlement Risks of Foreign Securities. The Fund's foreign securities are generally held outside the United States in the primary market for the securities in the custody of certain eligible foreign banks and trust companies ("foreign sub-custodians"), as permitted under the Investment Company Act of 1940 (the 1940 Act). Settlement practices for foreign securities may differ from those in the United States. Some countries have limited governmental oversight and regulation of industry practices, stock exchanges, depositories, registrars, brokers and listed companies, which increases the risk of corruption and fraud and the possibility of losses to the Fund. In particular, under certain circumstances, foreign securities may settle on a delayed delivery basis, meaning that the Fund may be required to make payment for securities before the Fund has actually received delivery of the securities or deliver securities prior to the receipt of payment. Typically, in these cases, the Fund will receive evidence of ownership in accordance with the generally accepted settlement practices in the local market entitling the Fund to delivery or payment at a future date, but there is a risk that the security will not be delivered to the Fund or that payment will not be received, although the Fund and its foreign sub-custodians take reasonable precautions to mitigate this risk. Losses can also result from lost, stolen or counterfeit securities; defaults by brokers and banks; failures or defects of the settlement system; or poor and improper record keeping by registrars and issuers.

  Share Blocking. Share blocking refers to a practice in certain foreign markets under which an issuer's securities are blocked from trading at the custodian or sub-custodian level for a specified number of days before and, in certain instances, after a shareholder meeting where a vote of shareholders takes place. The blocking period can last up to several weeks. Share blocking may prevent the Fund from buying or selling securities during this period, because during the time shares are blocked, trades in such securities will not settle. It may be difficult or impossible to lift blocking restrictions, with the particular requirements varying widely by country. As a consequence of these restrictions, the Investment Manager, on behalf of the Fund, may abstain from voting proxies in markets that require share blocking.

• Emerging Market Securities Risk – Securities issued by foreign governments or companies in emerging market countries, like Russia and those in Eastern Europe, the Middle East, Asia, Latin America or Africa, are more likely to have greater exposure to the risks of investing in foreign securities that are described in Foreign Securities Risk. In addition, emerging market countries are more likely to experience instability resulting, for example, from rapid social, political and economic development. Their economies are usually less mature and their securities markets are typically less developed with more limited trading activity than more developed countries. Emerging market securities tend to be more volatile than securities in more developed markets. Many emerging market countries are heavily dependent on international trade, which makes them more sensitive to world commodity prices and economic downturns in other countries.

  Operational and Settlement Risks of Securities in Emerging Markets. In addition to having less developed securities markets, banks in emerging markets that are eligible foreign sub-custodians may be recently organized, lack extensive operating experience or lack effective government oversight or regulation. In addition, there may be legal restrictions or limitations on the ability of the Fund to recover assets held in custody by a foreign sub-custodian in the event of the bankruptcy of the sub-custodian. Because settlement systems may be less organized than in developed markets and because delivery versus payment settlement may not be possible or reliable, there may be a greater risk that settlement may be delayed and that cash or securities of the Fund may be lost because of failures of or defects in the system, including fraud or corruption. Settlement systems in emerging markets also have a higher risk of failed trades. Ownership of Russian securities poses particular risks because ownership records are typically maintained in a decentralized fashion by registrars who may not be subject to effective governmental supervision leading to the possibility that the Fund may lose its ownership rights. In such a case, it may be difficult for the Fund to enforce any rights it may have against the registrar or issuer of the securities.

  Risks Related to Currencies and Corporate Actions in Emerging Markets. Risks related to currencies and corporate actions are also greater in emerging market countries than in developed countries. For example, some emerging market countries may have fixed or managed currencies that are not free-floating against the U.S. dollar. Further, certain currencies may not be traded internationally, or countries may have varying exchange rates. Some emerging market countries have a higher risk of currency devaluations, and some of these countries may experience sustained periods of high inflation or rapid changes in inflation rates which can have negative effects on a country's economy and securities markets. Corporate action procedures in emerging market countries may be less reliable and have limited or no involvement by the depositories and central banks. Lack of standard practices and payment systems can lead to significant delays in payment.

  Risks Related to Corporate and Securities Laws in Emerging Markets. Securities laws in emerging markets may be relatively new and unsettled and, consequently, there is a risk of rapid and unpredictable change in laws regarding foreign investment, securities regulation, title to securities and shareholder rights. Accordingly, foreign investors may be adversely affected by new or amended laws and regulations. In addition, the systems of corporate governance to which issuers in certain emerging markets are subject may be less advanced than the systems to which issuers located in more developed countries are subject, and therefore, shareholders of such issuers may not receive many of the protections available to shareholders of issuers located in more developed countries. These risks may be heightened in Russia.

• Opportunistic Investing Risk - Undervalued securities involve the risk that they may never reach their expected full market value, either because the market fails to recognize the security's intrinsic worth or the expected value was misgauged. Undervalued securities also may decline in price even though the Investment Manager believes they are already undervalued. Turnaround companies may never improve their fundamentals, may take much longer than expected to improve, or may improve much less than expected. Development stage companies could fail to develop and deplete their assets, resulting in large percentage losses.

• Currency Risk – Securities denominated in non-U.S. dollar currencies are subject to the risk that, for example, if the value of a foreign currency were to decline against the U.S. dollar, such decline would reduce the U.S. dollar value of any securities held by the Fund denominated in that currency.

Performance Information

The bar chart below and table on the following page show you how the Fund has performed in the past, and can help you understand the risks of investing in the Fund. The inception date for the Fund's Class I shares is September 27, 2010 and the inception date for the Fund's Class R4, Class R5 and Class Y shares is November 8, 2012. The returns shown for these share classes include the returns of the Fund's Class Z shares for periods prior to their inception dates. Except for differences in expenses, these share classes have annual returns substantially similar to those of Class Z shares, because all classes of the Fund's shares invest in the same portfolio of securities.

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 www.columbiamanagement.com.

The bar chart below shows you how the performance of the Fund's Class Z shares has varied from year to year.

Year by Year Total Return (%) as of December 31 Each Year

^[1]

Best and Worst Quarterly Returns During this Period

Best:    2nd quarter 2009:       28.11%

Worst:   4th quarter 2008:      -30.14%

Average Annual Total Return as of December 31, 2012

The table compares the Fund's returns for each period with those of the Standard & Poor's (S&P) MidCap 400® Index, the Fund's primary benchmark, and the S&P 500® Index. The S&P MidCap 400® Index is a market value-weighted index that tracks the performance of 400 mid-cap U.S. companies. The S&P 500® Index tracks the performance of 500 widely held, large-capitalization U.S. stocks. Although the Fund typically invests in companies with market capitalizations under $20 billion at the time of investment, the comparison to the S&P 500® Index is presented to show performance against a widely recognized market index.

Average Annual Total Returns (Columbia Acorn Select)	1 Year	5 Years	10 Years
Class Z Shares	17.15%	0.33%	8.62%
Class Z Shares returns after taxes on distributions	15.80%	(0.10%)	8.21%
Class Z Shares returns after taxes on distributions and sale of Fund shares	12.87%	0.20%	7.58%
Class A Shares	10.15%	(1.14%)	7.64%
Class B Shares	11.11%	(0.95%)	7.57%
Class C Shares	14.93%	(0.76%)	7.44%
Class I Shares	17.26%	0.39%	8.65%
Class R4 Shares	17.11%	0.32%	8.61%
Class R5 Shares	17.15%	0.33%	8.62%
Class Y Shares	17.14%	0.33%	8.62%
S&P MidCap 400® Index (reflects no deductions for fees, expenses or taxes)	17.88%	5.15%	10.53%
S&P 500® Index (reflects no deductions for fees, expenses or taxes)	16.00%	1.66%	7.10%

The after-tax returns shown in the table above are calculated using the highest historical individual U.S. federal marginal income tax rates 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-deferred accounts such as 401(k) plans or individual retirement accounts (IRAs). The after-tax returns are shown only for Class Z shares and will vary for other share classes.

[1] Contingent deferred sales charges (CDSC) on certain investments of between $1 million and $50 million redeemed within 18 months of purchase, charged as follows: 1.00% CDSC if redeemed within 12 months of purchase, and 0.50% CDSC if redeemed more than 12, but less than 18, months of purchase, with certain limited exceptions.

[2] This charge decreases over time.

[3] This charge applies to investors who buy Class C shares and redeem them within one year of purchase, with certain limited exceptions.

[1] Other expenses have been restated to reflect contractual changes to certain fees paid by the Fund.

[1] Year-to-date return as of March 31, 2013: 10.64%