# EDGAR Filing Document

**Accession Number:** 0000746458
**File Stem:** 0000746458-25-000019
**Filing Date:** 2025-9
**Character Count:** 15154
**Document Hash:** 46488aec5c5e69f7a6c4f0a021195aee
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000746458-25-000019.hdr.sgml**: 20250926

**ACCESSION NUMBER**: 0000746458-25-000019

**CONFORMED SUBMISSION TYPE**: 497K

**PUBLIC DOCUMENT COUNT**: 3

**FILED AS OF DATE**: 20250926

**DATE AS OF CHANGE**: 20250926

**EFFECTIVENESS DATE**: 20250926

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** AMERICAN CENTURY MUNICIPAL TRUST
- **CENTRAL INDEX KEY:** 0000746458

**ORGANIZATION NAME:**
- **EIN:** 776009794
- **STATE OF INCORPORATION:** MA
- **FISCAL YEAR END:** 0531

**FILING VALUES:**
- **FORM TYPE:** 497K
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 002-91229
- **FILM NUMBER:** 251349535

**BUSINESS ADDRESS:**
- **STREET 1:** 4500 MAIN STREET
- **CITY:** KANSAS CITY
- **STATE:** MO
- **ZIP:** 64111
- **BUSINESS PHONE:** 816-531-5575

**MAIL ADDRESS:**
- **STREET 1:** 4500 MAIN STREET
- **CITY:** KANSAS CITY
- **STATE:** MO
- **ZIP:** 64111

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** BENHAM MUNICIPAL TRUST
- **DATE OF NAME CHANGE:** 19940202

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** BENHAM NATIONAL TAX FREE TRUST
- **DATE OF NAME CHANGE:** 19920703

## Series and Classes Contracts Data

### TAX-FREE MONEY MARKET FUND (Series ID: S000006473)

| Class ID   | Class Name     | Ticker Symbol   |
|:---|:---|:---|
| C000017692 | INVESTOR CLASS | BNTXX           |

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| | |
|:---|:---|
| **Summary Prospectus&nbsp;&nbsp;&nbsp;&nbsp;** October 1, 2025<br>**American Century Investments**<sup>®</sup><br>**Tax-Free Money Market Fund** | ![newaci_logoblkf42.jpg](newaci_logoblkf42.jpg) |
| **Investor Class:** BNTXX |  |

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| | |
|:---|:---|
| 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, 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.  | 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, 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.  |
| &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;**Retail Investors**<br>americancentury.com/docs<br>1-800-345-2021 or 816-531-5575<br>prospectus@americancentury.com | **Financial Professionals**<br>americancentury.com/fadocs<br>1-800-345-6488<br>advisor_prospectus@americancentury.com |
| This summary prospectus incorporates by reference the fund's <u>[prospectus and statement of additional information](https://www.sec.gov/Archives/edgar/data/746458/000074645825000012/ck0000746458-20250926.htm)</u> (SAI), each dated October 1, 2025 (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 Form N-CSR for the fiscal year ended May 31, 2025. The fund's SAI and <u>[Form N-CSR](https://www.sec.gov/Archives/edgar/data/746458/000074645825000006/ck0000746458-20250531.htm)</u> may be obtained, free of charge, in the same manner as the prospectus. | This summary prospectus incorporates by reference the fund's <u>[prospectus and statement of additional information](https://www.sec.gov/Archives/edgar/data/746458/000074645825000012/ck0000746458-20250926.htm)</u> (SAI), each dated October 1, 2025 (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 Form N-CSR for the fiscal year ended May 31, 2025. The fund's SAI and <u>[Form N-CSR](https://www.sec.gov/Archives/edgar/data/746458/000074645825000006/ck0000746458-20250531.htm)</u> may be obtained, free of charge, in the same manner as the prospectus. |

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**Investment Objective**

The fund seeks safety of principal and high current income that is exempt from federal income tax.

**Fees and Expenses**

The following table describes the fees and expenses you may pay if you buy, hold and sell shares of the fund.

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| | |
|:---|:---|
| **Shareholder Fees** (fees paid directly from your investment) | **Shareholder Fees** (fees paid directly from your investment) |
|  | *Investor* |
| Maximum Annual Account Maintenance Fee<br>(waived if eligible investments total at least $25,000 or shareholder has elected electronic delivery) | $25 |

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| | |
|:---|:---|
| **Annual Fund Operating Expenses** (expenses that you pay each year as a percentage of your investment) | **Annual Fund Operating Expenses** (expenses that you pay each year as a percentage of your investment) |
|  | *Investor* |
| Management Fee | 0.49% |
| Distribution and Service (12b-1) Fees |  |
| Other Expenses | 0.00% |
| Total Annual Fund Operating Expenses | 0.49% |

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**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:

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| | | | | |
|:---|:---|:---|:---|:---|
|  | *1 year* | *3 years* | *5 years* | *10 years* |
| Investor Class | $50 | $157 | $275 | $617 |

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**Principal Investment Strategies**

The fund is a retail money market fund that invests in municipal money market securities. The securities purchased by the fund are subject to the maturity, quality, diversification, and other requirements of Rule 2a-7 under the Investment Company Act of 1940, as amended. Although the fund seeks to maintain a $1.00 share price, there is no guarantee it will be able to do so.

Under normal market conditions, the fund invests at least 80% of its net assets in cash-equivalent, high-quality debt securities with interest payments exempt from federal income tax. Cities, counties, other municipalities and U.S. territories may issue these securities. A high-quality debt security is one that an independent rating agency rates in its top two credit quality categories or that the advisor determines to be of comparable credit quality.

The portfolio managers also may buy cash-equivalent, high-quality debt securities with interest payments exempt from regular federal income tax, but not exempt from the federal alternative minimum tax. Cities, counties, and other municipalities usually issue these securities (called private activity bonds) to fund for-profit private projects, such as hospitals and athletic stadiums. The fund may invest no more than 20% of its assets in these securities.

When determining whether to buy or sell a security, portfolio managers may consider current and anticipated changes in interest rates, issuer credit quality, comparable alternatives, diversification limits, and general market conditions.

**Principal Risks**

• **Low Yield Risk** – Because high-quality debt securities are among the safest securities available, the interest they pay is among the lowest for income-paying securities. Accordingly, the yield on this fund will likely be lower than the yield on funds that invest in lower-quality or longer-term securities.

• **Municipal Securities Risk** – Because the fund invests principally in municipal securities, it 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.

• **Interest Rate Risk** – Interest rate risk means that the value of debt securities and the funds that hold them decline as interest rates rise. A period of rising interest rates may negatively affect the fund's performance.

• **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.

• **Liquidity Risk** – Liquidity risk means that during periods of market turbulence or unusually low trading activity, 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. Changing regulatory and market conditions may adversely affect the liquidity of the fund's investments. If liquidity decreases too much, the fund may impose a fee on the sale of shares or temporarily suspend redemptions.

• **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. The fund may sell securities that lose their tax-exempt statuses at inopportune times, which may cause tax consequences or a decrease in the fund's value.

• **Principal Loss Risk** – You could lose money by investing in the fund. Although the fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so. The fund may impose a fee upon sale of your shares. An investment in the fund is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The fund's sponsor is not required to reimburse the fund for losses, and you should not expect that the sponsor will provide financial support to the fund at any time, including during periods of market stress.

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**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 fund's past performance is not necessarily an indication of how the fund will perform in the future. For current performance information, including yields, 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**

![chart-64bb746fe8d44f158e9a.jpg](chart-64bb746fe8d44f158e9a.jpg)

**Highest Performance Quarter (4Q 2023): 0.83%&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Lowest Performance Quarter (1Q 2021): 0.00%**

**As of June 30, 2025, the most recent calendar quarter end, the fund's Investor Class year-to-date return was 1.21%.**

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| | | | |
|:---|:---|:---|:---|
| **Average Annual Total Returns** <br>*For the calendar year ended December 31, 2024* | *1 year* | *5 years* | *10 years* |
| Investor Class | 3.06% | 1.45% | 0.99% |

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**Investment Advisor**

American Century Investment Management, Inc.

**Purchase and Sale of Fund Shares**

The fund is only available for purchase by accounts that are beneficially owned by natural persons. The fund may involuntarily redeem shares in any account not beneficially owned by a natural person.

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 ($1,000 for Coverdell Education Savings Accounts and IRAs). However, American Century Investments will waive the fund minimum if you make an initial investment of at least $500 and continue to make automatic investments of at least $100 a month until reaching the fund minimum. Investors opening accounts through financial intermediaries may open an account with $250, 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.

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.

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

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The fund may impose a liquidity fee of up to 2% on fund redemptions if the fund's Board of Trustees, or its delegate, determines that a liquidity fee is in the best interests of the fund. The Board of Trustees has delegated liquidity fee determinations to the advisor or its officers.

**Tax Information**

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

If you hold your fund shares through a tax-deferred investment plan, such as a 401(k) plan or an IRA, any distributions received from the fund may be taxable as ordinary income upon withdrawal from the tax-deferred plan, regardless of whether the distributions were tax-exempt when earned.

**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.

<sup>©</sup>2025 American Century Proprietary Holdings, Inc. All rights reserved.

CL-SUM-89885 2510

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