High-Yield Municipal Fund

The advisor will waive the portion of the fund's management fee equal to the expenses attributable to the management fees of the American Century funds in which the fund invests. The amount of this waiver fluctuates depending on the fund's daily allocation to other American Century funds. This waiver is expected to remain in effect permanently and it cannot be terminated without the approval of the Board of Trustees.

The lower-rated securities in which the fund invests are subject to greater default and liquidity risk, because the issuers of high-yield securities are more sensitive to real or perceived economic changes.

Generally, as interest rates rise, the value of the securities held in the fund will decline. The opposite is true when interest rates decline.

The gross expense ratio is the fund's total annual operating costs, expressed as a percentage of the fund's average net assets for a given time period. It is gross of any fee waivers or expense reimbursement. The net expense ratio is the expense ratio after the application of any waivers or reimbursement. This is the actual ratio that investors paid during the fund's most recent fiscal year. Please see the prospectus for more information.

^W2 Minimum initial investment is $1,000 for IRA and CESA accounts, and $2,500 for non-retirement accounts, but these minimums are waived with an initial investment of at least $500 per account and automatic investments of at least $100 per month. If your account balance falls below the minimum, or if you cancel your automatic monthly investment plan prior to reaching the minimum, American Century Investments may redeem the account and send the proceeds to you. Prior to doing so, we will notify you and give you 90 days to meet the minimum or reinstate your automatic monthly investment plan.