Mutual Fund Summary Prospectus (497k)

Summary Prospectus October 31, 2013

American Century Investments ^®

Disciplined Growth Fund

Investor Class: ADSIX

Institutional Class: ADCIX

A Class: ADCVX

C Class: ADCCX

R Class: ADRRX

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 the web addresses listed below. You can also get this information at no cost by calling or sending an email request. The fund’s prospectus and other information are also available from financial intermediaries (such as banks and broker-dealers) through which shares of the fund may be purchased or sold.

Retail Investors

americancentury.com/funds/fund_reports.jsp

1-800-345-2021 or 816-531-5575

prospectus@americancentury.com

Financial Professionals

americancentury.com/ipro/funds/fund_reports_mf.jsp

1-800-345-6488

advisor_prospectus@americancentury.com

This summary prospectus incorporates by reference the fund’s prospectus and statement of additional information (SAI), each dated October 31, 2013 (as supplemented at the time you receive this summary prospectus), as well as the Report of Independent Registered Public Accounting Firm and the financial statements included in the fund’s annual report to shareholders, dated June 30, 2013. The fund's SAI and annual report may be obtained, free of charge, in the same manner as the prospectus.

Investment Objective

The fund seeks long-term capital growth.

Fees and Expenses

The following table describes the fees and expenses 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 American Century Investments funds. More information about these and other discounts is available from your financial professional and in Calculation of Sales Charges on page 13 of the fund’s prospectus and Sales Charges in Appendix B of the statement of additional information.

Shareholder Fees (fees paid directly from your investment)
	Investor	Institutional	A	C	R
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None	5.75%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the lower of the original offering price or redemption proceeds when redeemed within one year of purchase)	None	None	None ¹	1.00%	None
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $10,000)	$25	None	None	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
	Investor	Institutional	A	C	R
Management Fee	1.02%	0.82%	1.02%	1.02%	1.02%
Distribution and Service (12b-1) Fees	None	None	0.25%	1.00%	0.50%
Other Expenses	0.01%	0.01%	0.01%	0.01%	0.01%
Total Annual Fund Operating Expenses	1.03%	0.83%	1.28%	2.03%	1.53%

¹	^{Investments of $1 million or more may be subject to a contingent deferred sales charge of 1.00% if the shares are redeemed within one year of the date of the purchase.}

Example

The example below is intended to help you compare the costs of investing in the fund with the costs 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, that you earn a 5% return each year, and that the fund’s operating expenses remain the same. 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
Investor Class	$105	$328	$569	$1,259
Institutional Class	$85	$265	$461	$1,026
A Class	$698	$958	$1,238	$2,031
C Class	$207	$638	$1,094	$2,355
R Class	$156	$484	$835	$1,822

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 94% of the average value of its portfolio.

Principal Investment Strategies

In selecting stocks for the fund, the portfolio managers initially identify an eligible universe of growth stocks then use quantitative management techniques in a two-step process. First, the managers rank stocks, primarily large capitalization, publicly traded U.S. companies with a market capitalization greater than $2 billion, from most attractive to least attractive based on an objective set of measures, including each stock’s value, quality, growth, and momentum. Second, the portfolio managers use a quantitative model to build a portfolio of stocks from the ranking described above that they believe will provide the optimal balance between risk and expected return.

The portfolio managers generally sell a stock when they believe it has become less attractive relative to other opportunities, its risk characteristics outweigh its return opportunity or specific events alter its prospects.

Principal Risks

•	Style Risk – If at any time the market is not favoring the fund’s quantitative investment style, the fund’s gains may not be as big as, or its losses may be bigger than, those of other equity funds using different investment styles.
•	Investment Process Risk – Stocks selected by the portfolio managers using quantitative models may perform differently than expected due to the portfolio managers' judgments regarding the factors used in the models, the weight placed on each factor, changes from the factors' historical trends, and technical issues with the construction and implementation of the models (including, for example, data problems and/or software or other implementation issues). There is no guarantee that the use of the quantitative model will result in effective investment decisions for the fund. Additionally, the commonality of portfolio holdings across quantitative investment managers may amplify losses.
•	Benchmark Correlation – The fund’s performance will be tied to the performance of its benchmark, the Russell 1000 ^® Growth Index. If the fund’s benchmark goes down, it is likely that the fund’s performance will go down.
•	Growth Stocks – Investments in growth stocks may involve special risks and their prices tend to fluctuate more dramatically than the overall stock market.
•	Market Risk – The value of the fund’s shares will go up and down based on the performance of the companies whose securities it owns and other factors generally affecting the securities market.
•	Price Volatility – The value of the fund’s shares may fluctuate significantly in the short term.
•	Principal Loss – At any given time your shares may be worth less than the price you paid for them. In other words, it is possible to lose money by investing in the fund.

An investment in the fund is not a bank deposit, and it is not insured or guaranteed by the Federal Deposit Insurance Corporation (FDIC) or any other government agency.

Fund Performance

The following bar chart and table provide some indication of the risks of investing in the fund. The bar chart shows changes in the fund’s performance from year to year for Investor Class shares. The table shows how the fund’s average annual returns for the periods shown compared with those of a broad measure of market performance. The fund’s past performance (before and after taxes) is not necessarily an indication of how the fund will perform in the future. For current performance information, please visit americancentury.com.

Sales charges and account fees, if applicable, are not reflected in the bar chart. If those charges were included, returns would be less than those shown.

Calendar Year Total Returns

Highest Performance Quarter
(1Q 2012): 17.16%

Lowest Performance Quarter
(4Q 2008): -23.62%

As of September 30, 2013, the most

recent calendar quarter end, the

fund’s Investor Class year-to-date

return was 21.84%.

Average Annual Total Returns
For the calendar year ended December 31, 2012	1 year	5 years	Since Inception	Inception Date
Investor Class Return Before Taxes	15.72%	2.84%	5.69%	09/30/2005
Return After Taxes on Distributions	15.56%	2.76%	5.46%	09/30/2005
Return After Taxes on Distributions and Sale of Fund Shares	10.42%	2.42%	4.86%	09/30/2005
Institutional Class Return Before Taxes	15.91%	3.06%	5.90%	09/30/2005
A Class ¹ Return Before Taxes	8.86%	1.40%	4.58%	09/30/2005
C Class Return Before Taxes	14.61%	1.83%	1.56%	09/28/2007
R Class Return Before Taxes	15.12%	2.34%	5.17%	09/30/2005
Russell 1000 ^® Growth Index (reflects no deduction for fees, expenses or taxes)	15.26%	3.12%	5.41%	09/30/2005

¹	Prior to September 4, 2007, this class was referred to as the Advisor Class and did not have a front-end sales charge. Performance has been restated to reflect this charge.

The after-tax returns are shown only for Investor Class shares. After-tax returns for other share classes will vary. 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 are not relevant to investors who hold their fund shares through tax-deferred arrangements, such as 401(k) plans or IRAs.

Portfolio Management

Investment Advisor

American Century Investment Management, Inc.

Portfolio Managers

William Martin , CFA, Senior Vice President and Senior Portfolio Manager, has been a member of the team that manages the fund since 2005.

Lynette Pang , CFA, Portfolio Manager, has been a member of the team that manages the fund since 2005.

Purchase and Sale of Fund Shares

You may purchase or redeem shares of the fund on any business day through our website at americancentury.com, in person (at one of our Investor Centers), by mail (American Century Investments, P.O. Box 419200, Kansas City, MO 64141-6200), by telephone at 1-800-345-2021 (Investor Services Representative) or 1-800-345-3533 (Business, Not-For-Profit and Employer-Sponsored Retirement Plans), or through a financial intermediary. Shares may be purchased and redemption proceeds received by electronic bank transfer, by check or by wire.

Unless otherwise specified below, the minimum initial investment amount to open an account is $2,500 ($2,000 for Coverdell Education Savings Accounts). Investors opening accounts through financial intermediaries may open an account with $250 for all classes except the Institutional Class, but the financial intermediaries may require their clients to meet different investment minimums. The minimum may be waived for broker-dealer sponsored wrap program accounts, fee based accounts, and accounts through bank/trust and wealth management advisory organizations.

The minimum initial investment amount for Institutional Class is generally $5 million ($3 million for endowments and foundations), but the minimum may be waived if you, or your financial intermediary if you invest through an omnibus account, have an aggregate investment in the American Century family of funds of $10 million or more.

For all share classes, there is no minimum initial investment amount for certain employer-sponsored retirement plans, however, financial intermediaries or plan recordkeepers may require plans to meet different minimums. For purposes of fund minimums, employer-sponsored retirement plans do not include SEP IRAs, SIMPLE IRAs or SARSEPs.

There is a $50 minimum for subsequent purchases, except that there is no subsequent purchase minimum for financial intermediaries or employer-sponsored retirement plans.

Tax Information

Fund distributions are generally taxable as ordinary income or capital gains, unless you are investing through a tax-deferred account such as a 401(k) or individual retirement account (in which case you may be taxed upon withdrawal of your investment from such 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, insurance company, plan sponsor or financial professional), the fund and its related companies 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 salesperson to recommend the fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.