summaypro.htm

Summary Prospectus October 1, 2010 American Century Investments® Long-Term Tax-Free Fund
Investor Class: ACLVX Institutional Class: ACLSX	A Class: MMBAX B Class: MMDBX (closed)	C Class: ACTCX

	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 1, 2010 (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 May 31, 2010. 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 a high level of current income exempt from federal income taxes, consistent with preservation of capital.

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 $100,000 in American Century Investments funds. More information about these and other discounts, as well as variations in charges that may apply to purchases of $1 million or more, is available from your financial professional and in Calculation of Sales Charges on page 12 of the fund’s prospectus and Sales Charges on page 54 of the statement of additional information. The fund's B Class shares are not available for purchase, except through exchanges and dividend reinvestments.

Shareholder Fees (fees paid directly from your investment)
	Investor	Institutional	A	B	C
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None	4.50%	None	None
Maximum Deferred Sales Charge (Load) (as a percentage of the original offering price for B Class shares or the lower of the original offering price or redemption proceeds for C Class shares)	None	None	None	5.00%	1.00%
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	B	C
Management Fee	0.48%	0.28%	0.48%	0.48%	0.48%
Distribution and Service (12b-1) Fees	None	None	0.25%	1.00%	1.00%
Other Expenses	0.00%	0.00%	0.00%	0.00%	0.00%
Total Annual Fund Operating Expenses	0.48%	0.28%	0.73%	1.48%	1.48%

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 (unless otherwise indicated), 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	$49	$154	$269	$604
Institutional Class	$29	$90	$158	$356
A Class	$521	$673	$838	$1,316
B Class	$551	$769	$909	$1,564
B Class (if shares not redeemed)	$151	$469	$809	$1,564
C Class	$151	$469	$809	$1,767

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 50% of the average value of its portfolio.

Principal Investments, Principal Risks and Performance

Under normal market conditions, the fund will invest at least 80% of the value of its net assets (plus any borrowings for investment purposes) in investment-grade municipal obligations with interest payments exempt from federal taxes. The fund will typically invest in long-term debt securities. Under normal market conditions, the fund will maintain a weighted average maturity of more than ten years.

Although the fund invests primarily in investment-grade securities, up to 20% of the value of the fund’s net assets may be invested in below investment-grade securities (BB and below). The fund also may invest in securities which, while not rated, are determined by the investment advisor to be of comparable quality to those rated below investment-grade.

When determining whether to sell a security, portfolio managers consider, among other things, current and anticipated changes in interest rates, the credit quality of a particular issuer, comparable alternatives, general market conditions and any other factor deemed relevant by the portfolio managers.

The fund’s principal risks include

•	Credit Risk – Debt securities, even investment-grade debt securities, are subject to credit risk. Credit risk is the risk that the inability or perceived inability of the issuer to make interest and principal payments will cause the value of the securities to decrease. As a result, the fund’s share price could also decrease. Changes in the credit rating of a debt security held by the fund could have a similar effect.
•	Interest Rate Risk – Investments in debt securities are also sensitive to interest rate changes. Generally, the value of debt securities and the funds that hold them decline as interest rates rise. Because this fund has a longer weighted average maturity, it is likely to be more sensitive to interest rate changes.
•	Municipal Securities Risk – The fund invests primarily in municipal securities and will be sensitive to events that affect municipal markets, including legislative or political changes and the financial condition of the issuers of municipal securities. By investing primarily in municipal securities, the fund may have a higher level of risk than funds that invest in a larger universe of securities.
•	Loss of Tax Exemptions Risk – There is no guarantee that all of the fund’s income will be exempt from federal or state income taxes. Income from municipal bonds held by the fund could be declared taxable because of unfavorable changes in tax laws, adverse interpretations by the Internal Revenue Service or state tax authorities, or noncompliant conduct of a bond issuer.
•	Liquidity Risk – The fund may also be subject to liquidity risk. During periods of market turbulence or unusually low trading activity, in order to meet redemptions it may be necessary for the fund to sell securities at prices that could have an adverse effect on the fund’s share price.
•	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.

Annual Total Returns

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 A 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, including yields, 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.

Highest Performance Quarter

(3Q 2009): 7.71%

Lowest Performance Quarter

(3Q 2008): -3.27%

As of June 30, 2010, the most

recent calendar quarter end,

the fund’s A Class year-to-date

return was 3.20%.

For the calendar year ended December 31, 2009	1 Year	5 Years	10 Years	Since Inception	Inception Date
A Class Return Before Taxes	7.50%	2.65%	4.87%	4.96%	03/31/1997
Return After Taxes on Distributions	7.50%	2.65%	4.63%	4.69%	03/31/1997
Return After Taxes on Distributions and Sale of Fund Shares	6.23%	2.77%	4.58%	4.65%	03/31/1997
Investor Class Return Before Taxes	12.83%	—	—	4.37%	04/03/2006
Institutional Class Return Before Taxes	13.05%	—	—	4.58%	04/03/2006
B Class Return Before Taxes	7.71%	2.66%	4.63%	4.62%	03/31/1997
C Class Return Before Taxes	11.71%	—	—	3.34%	04/03/2006
Barclays Capital Municipal Bond Index (reflects no deduction for fees, expenses or taxes)	12.91%	4.32%	5.75%	5.57%	03/31/1997

The after-tax returns are shown only for A 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

Steven M. Permut, Senior Vice President and Senior Portfolio Manager, has shared primary responsibility for the management of the fund since 2006, and has served on teams managing fixed-income investments since joining the advisor in 1987.

Alan Kruss, Vice President and Portfolio Manager, has shared primary responsibility for the management of the fund since 2008, and has served on teams managing fixed-income investments since joining the advisor in 1997.

Joseph Gotelli, Vice President and Portfolio Manager, has shared primary responsibility for the management of the fund since 2008, and has served on teams managing fixed-income investments since joining the advisor in 2008.

Purchase and Sale of Fund Shares

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

Unless otherwise specified below, the minimum initial investment amount to open an account is $5,000. Financial intermediaries may open an account with $250, but may require their clients to meet different investment minimums. Broker-dealer sponsored wrap program accounts and fee based accounts (in classes other than Institutional Class) do not have a minimum purchase amount. The minimum initial amount for Coverdell Education Savings Accounts (CESA) is $5,000 unless the account is opened through a financial intermediary. To establish a CESA, you must exchange from another American Century Investments CESA or roll over a minimum of $5,000 in order to meet the fund’s minimum. The fund is not available for employer-sponsored retirement plans and generally is inappropriate for tax-deferred accounts, such as IRAs and 403(b) custodial accounts.

The minimum initial amount for Institutional Class is generally $5 million ($3 million for endowments and foundations).

There is a $50 minimum for subsequent purchases, except that there is no subsequent purchase minimum for financial intermediaries or employer-sponsored retirement plans. For purposes of fund minimums, employer-sponsored retirement plans do not include SEP IRAs, SIMPLE IRAs or SARSEPs.

Tax Information

The fund intends to distribute income that is exempt from regular federal income tax, however, fund distributions may be subject to capital gains tax. A portion of the fund’s distributions may be subject to federal income tax or to the federal alternative minimum tax.

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 Web site for more information.

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