Summary Prospectus by Investment Company - Form 497K

Summary Prospectus August 1, 2024 American Century Investments® Short Duration Strategic Income Fund
Investor Class: ASDVX I Class: ASDHX	Y Class: ASYDX A Class: ASADX	C Class: ASCDX R Class: ASDRX	R5 Class: ASDJX R6 Class: ASXDX

	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.
	Retail Investors americancentury.com/docs 1-800-345-2021 or 816-531-5575 [email protected]	Financial Professionals americancentury.com/fadocs 1-800-345-6488 [email protected]
	This summary prospectus incorporates by reference the fund's prospectus and statement of additional information (SAI), each dated August 1, 2024 (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 March 31, 2024. 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 income. As a secondary objective, the fund seeks long-term capital appreciation.

Fees and Expenses

The following table describes the fees and expenses you may pay if you buy, hold and sell shares of the fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. 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 is available from your financial professional and in Calculation of Sales Charges on page 17 of the fund's prospectus, Appendix A 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	I	Y	A	C	R	R5	R6
Maximum Sales Charge (Load) Imposed on Purchases (as a percentage of offering price)	None	None	None	2.25%	None	None	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	None¹	1.00%	None	None	None
Maximum Annual Account Maintenance Fee (waived if eligible investments total at least $25,000 or shareholder has elected electronic delivery)	$25	None	None	None	None	None	None	None

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
	Investor	I	Y	A	C	R	R5	R6
Management Fee	0.51%	0.41%	0.31%	0.51%	0.51%	0.51%	0.31%	0.26%
Distribution and Service (12b-1) Fees	None	None	None	0.25%	1.00%	0.50%	None	None
Other Expenses	0.01%	0.01%	0.01%	0.01%	0.01%	0.01%	0.01%	0.01%
Total Annual Fund Operating Expenses	0.52%	0.42%	0.32%	0.77%	1.52%	1.02%	0.32%	0.27%

1 Purchases of $500,000 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	$53	$167	$291	$653
I Class	$43	$135	$236	$530
Y Class	$33	$103	$180	$406
A Class	$302	$466	$644	$1,158
C Class	$155	$481	$830	$1,609
R Class	$104	$325	$564	$1,248
R5 Class	$33	$103	$180	$406
R6 Class	$28	$87	$152	$344

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 214% of the average value of its portfolio.

Principal Investment Strategies

The fund invests in corporate bonds and notes, government securities, collateralized loan obligations, collateralized mortgage obligations and securities backed by mortgages or other assets. The fund may invest in both investment-grade and high-yield, non-money market debt securities. Investment grade securities are those that have been rated in one of the top four credit quality categories by an independent rating agency or determined by the advisor to be of comparable credit quality. High-yield securities, which are also known as "junk bonds", are those that have been rated by an independent rating agency below the highest four categories or determined by the advisor to be of similar quality.

The debt securities in which the fund invests may be payable in U.S. or foreign currencies.

The fund may also invest in certain equity securities such as preferred stock, convertible securities or equity equivalents provided that such investments are consistent with the fund's investment objectives. Convertible securities in which the fund may invest include contingent convertible securities (sometimes referred to as CoCos or Additional Tier 1 Instruments).

The fund may invest in securities issued or guaranteed by the U.S. Treasury and certain U.S. government agencies or instrumentalities such as the Government National Mortgage Association (Ginnie Mae). Ginnie Mae is supported by the full faith and credit of the U.S. government. Securities issued or guaranteed by other U.S. government agencies or instrumentalities, such as the Federal National Mortgage Association (Fannie Mae), the Federal Home Loan Mortgage Corporation (Freddie Mac), and the Federal Home Loan Bank (FHLB) are not guaranteed by the U.S. Treasury or supported by the full faith and credit of the U.S. government. However, they are authorized to borrow from the U.S. Treasury to meet their obligations.

In addition to the securities listed above, the fund may also invest in bank loans.

The fund may also utilize derivative instruments provided that such investments are in keeping with the fund's investment objectives. Such derivative instruments may include options, futures contracts, options on futures contracts, and swaps (such as credit default swaps either on a single issuer or a securities index). The fund may use foreign currency exchange contracts to shift investment exposure from one currency into another for hedging purposes or to enhance returns.

The weighted average duration of the fund's portfolio must be three years or shorter. Duration is an indication of the relative sensitivity of a security's market value to changes in interest rates. The longer the weighted average duration of the fund's portfolio, the more sensitive its market value is to interest rate fluctuations. Duration is different from maturity in that it attempts to measure the interest rate sensitivity of a security, as opposed to its expected final maturity. For example, if the weighted average duration of the fund's portfolio is two years, a 2% change in the value of the fund's portfolio would be expected for every 1% change in interest rates.

The portfolio managers select securities using an approach that integrates macroeconomic inputs, technical analysis of the relative value among various sectors, and fundamental research on individual securities. The macroeconomic framework provides interest rate and duration guidelines for the fund by analyzing economic activity, inflation, and monetary policy. Portfolio managers select individual securities using in-depth fundamental analysis designed to provide a detailed understanding of the credit worthiness of a security and its related market. As the market environment and investment opportunities change, portfolio managers buy and sell securities to meet the fund's evolving sector allocations and credit quality standards.

The portfolio managers may engage in hedging of portfolio positions, which usually involves entering into a derivative transaction that has the opposite characteristic of the position being hedged. The net effect of the two positions is intended to reduce or eliminate the exposure created by the first position.

To gain exposure to certain segments of the fixed-income market, the fund may invest in other American Century funds (affiliated funds), unaffiliated funds, securities and other financial instruments.

Principal Risks

•Interest Rate Risk - Investments in debt securities are sensitive to interest rate changes. Generally, 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 - The inability or perceived inability of a security's issuer to make interest and principal payments may cause the value of the security 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.

•High-Yield Risk - Issuers of high-yield securities are more vulnerable to real or perceived economic changes (such as an economic downturn or a prolonged period of rising interest rates), political changes or adverse developments specific to an issuer. These factors may be more likely to cause an issuer of low quality bonds to default on its obligations.

•Prepayment and Extension Risk - The fund may invest in debt securities backed by mortgages or other assets. If these underlying assets are prepaid, the fund may benefit less from declining interest rates than funds of similar duration that invest less heavily in mortgage- and asset-backed securities. Conversely, an issuer may exercise its right to pay principal on an obligation held by the fund later than expected (extend the obligation) especially in periods of rising interest rates. These events may lengthen the duration (i.e. interest rate sensitivity) and potentially reduce the value of these securities.

•Derivatives Risk -The use of derivative instruments involves risks different from, or possibly greater than, the risks associated with investing directly in securities and other traditional instruments. Derivatives are subject to a number of risks, including liquidity, interest rate, market, credit, and correlation risk. Derivatives can be highly illiquid and difficult to unwind or value, and changes in the value of a derivative held by the fund may not correlate with the value of the underlying instrument or the fund's other investments. Derivatives used for hedging or risk management may not operate as intended, may expose the fund to other risks, and may be insufficient to protect the fund from the risks they were intended to hedge.

•Collateralized Obligations Risk - Collateralized obligations, such as collateralized loan obligations (CLOs), are subject to credit, interest rate, valuation, and prepayment and extension risks. These securities also are subject to risk of default on the underlying asset, particularly during periods of economic downturn. The market value of collateralized obligations may be affected by, among other things, changes in the market value of the underlying assets held by the collateralized obligations, changes in the distributions on the underlying assets, defaults and recoveries on the underlying assets, capital gains and losses on the underlying assets, prepayments on underlying assets and the availability, and prices and interest rates of underlying assets. Some of the collateralized obligations in which the fund invests may be covenant-lite loans. Covenant-lite loans contain fewer or less restrictive constraints on the borrower. The fund may have fewer rights against a borrower and an accompanying greater risk of loss when it invests in covenant-lite loans.

•Convertible Securities Risk - The value of convertible securities may rise and fall with the market value of the underlying stock or, like a debt security, vary with changes in interest rates and the credit quality of the issuer. A convertible security tends to perform more like a stock when the underlying stock price is high relative to the conversion price and more like a debt security when the underlying stock price is low relative to the conversion price. Contingent convertible securities (sometimes referred to as CoCos or Additional Tier 1 Instruments) are subject to additional risks. Under certain circumstances, CoCos may be subject to automatic write-down of the principal amount or value of the securities, sometimes to zero, thereby canceling the securities. If such an event occurs, the fund may not have any rights to repayment of the principal amount of the securities that has not become due. Additionally, the fund may not be able to collect interest payments or dividends on such securities.

•Counterparty Risk - If the fund enters into financial contracts, the fund will be subject to the credit risk presented by counterparties.

•Liquidity Risk - 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. In addition, when the market for certain investments is illiquid, the fund may be unable to achieve its desired level of exposure to a certain sector. Illiquid securities may be difficult to value. Changing regulatory and market conditions, including increases in interest rates and credit spreads, may adversely affect the liquidity of the fund's investments.

•Bank Loan Risk - The market for bank loans may not be highly liquid and the fund may have difficulty selling them. Bank loans may not be considered securities, thus the fund may not be afforded anti-fraud protections available under the federal securities laws.In connection with purchasing loan participations, the fund generally will have no right to enforce compliance by borrowers with loan terms nor any set off rights, and the fund may not benefit directly from any posted collateral. As a result, the fund may be subject to the credit risk of both the borrower and the lender selling the participation. Bank loan transactions may take more than seven days to settle, meaning that proceeds would be unavailable to make additional investments or meet redemptions.

•Foreign Securities Risk - Foreign securities are generally riskier than U.S. securities. Political events (such as civil unrest, national elections and imposition of exchange controls), social and economic events (such as labor strikes and rising inflation), natural disasters and public health emergencies occurring in a country where the fund invests could cause the fund's investments in that country to experience losses. Securities of foreign issuers may be less liquid, more volatile and harder to value than U.S. securities.

•Currency Risk - Because the fund may invest in securities denominated in foreign currencies, the fund could experience gains or losses based solely on changes in the exchange rate between foreign currencies and the U.S. dollar.

•Convertible Securities Risk - The fund may invest in convertible securities, which may be affected by changes in interest rates, the credit of the issuer, and the value of the underlying common stock. In addition, because these securities are convertible into common stock, they are subject to general stock market risk, though to a lesser degree.

•Market Risk -The value of securities owned by the fund may go up and down, sometimes rapidly or unpredictably. Market risks, including political, regulatory, economic and social developments, can affect the value of the fund's investments. Natural disasters, public health emergencies, war, terrorism and other unforeseeable events may lead to increased market volatility and may have adverse long-term effects on world economies and markets generally.

•Redemption Risk -The fund may need to sell securities at times it would not otherwise do so to meet shareholder redemption requests. Selling securities to meet such redemptions may cause the fund to experience a loss, increase the fund's transaction costs or have tax consequences. To the extent that a large shareholder (including a fund of funds or 529 college savings plan) invests in the fund, the fund may experience relatively large redemptions as such shareholder reallocates its assets.

•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 table also shows returns for the Bloomberg U.S. 1-3 Year Government/Credit Bond Index, which the advisor considers to be more representative of the fund's investment strategy. 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.

Calendar Year Total Returns

Highest Performance Quarter (2Q 2020): 4.93% Lowest Performance Quarter (1Q 2020): -3.39%

As of June 30, 2024, the most recent calendar quarter end, the fund's Investor Class year-to-date return was 2.25%.

Average Annual Total Returns For the calendar year ended December 31, 2023	1 year	5 years	Since Inception	Inception Date
Investor Class Return Before Taxes	5.74%	2.43%	1.95%	07/28/2014
Return After Taxes on Distributions	3.69%	1.05%	0.64%	07/28/2014
Return After Taxes on Distributions and Sale of Fund Shares	3.36%	1.28%	0.91%	07/28/2014
I Class1 Return Before Taxes	5.84%	2.53%	2.05%	04/10/2017
Y Class1Return Before Taxes	5.95%	2.60%	2.15%	04/10/2017
A Class Return Before Taxes	3.10%	1.69%	1.46%	07/28/2014
C Class2 Return Before Taxes	4.69%	1.41%	1.06%	07/28/2014
R Class Return Before Taxes	5.21%	1.90%	1.45%	07/28/2014
R5 Class Return Before Taxes	5.95%	2.61%	2.16%	07/28/2014
R6 Class Return Before Taxes	6.12%	2.69%	2.22%	07/28/2014
Bloomberg U.S. Aggregate Bond Index3 (reflects no deduction for fees, expenses or taxes)	5.53%	1.10%	1.50%	07/28/2014
Bloomberg U.S. 1-3 Year Government/Credit Bond Index (reflects no deduction for fees, expenses or taxes)	4.61%	1.51%	1.29%	07/28/2014

1Historical performance for the I and Y Classes prior to their inception is based on the performance of R5 Class shares. I and Y Class performance has been adjusted to reflect differences in expenses between classes, if applicable. Since inception performance for the I and Y Class is based on the R5 Class inception date.

2 C Class shares automatically convert to A Class shares after approximately eight years. All returns for periods greater than eight years reflect this conversion.

3The fund's broad-based securities market index changed from the Bloomberg U.S. 1-3 Year Government/Credit Bond Index to the Bloomberg U.S. Aggregate Bond Index as a result of recent regulatory changes requiring that such index represent the overall applicable securities market.

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

Jason Greenblath, Vice President and Senior Portfolio Manager, has served on teams managing fixed-income investments since joining the advisor in 2019.

Paul Norris, Vice President and Senior Portfolio Manager, has been a member of the team that manages the funds since 2023.

Charles Tan, Senior Vice President and Co-Chief Investment Officer, Global Fixed Income, has served on teams managing fixed-income investments since joining the advisor in 2018.

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 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 for the Investor, A, C and R Classes, 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 the I Class is generally $5 million ($3 million for endowments and foundations), but the minimum may be waived if you have an aggregate investment in the American Century family of funds of $10 million or more ($5 million for endowments and foundations). This includes accounts held directly with American Century and those held through a financial intermediary.

There is no minimum initial investment amount for Y, R5 or R6 Class shares.

For the Investor, A, C, R, R5 and R6 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. Employer-sponsored retirement plans are not eligible to purchase I or Y Class shares.

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 for investments in all classes except the Y and R6 Classes. 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.

©2024 American Century Proprietary Holdings, Inc. All rights reserved.

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