Summary Prospectus |  September 15, 2025

Schwab® Treasury Inflation Protected Securities Index Fund

Ticker Symbol: SWRSX

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, Statement of Additional Information (SAI), reports to shareholders and other information about the fund online at www.schwabassetmanagement.com/prospectus. You can also obtain this information at no cost by calling 1-866-414-6349 or by sending an email request to orders@mysummaryprospectus.com. If you purchase or hold fund shares through a financial intermediary, the fund’s prospectus, SAI, reports to shareholders and other information about the fund are available from your financial intermediary.

The fund’s prospectus and SAI, both dated December 20, 2024, as supplemented, include a more detailed discussion of fund investment policies and the risks associated with various fund investments. The prospectus and SAI are incorporated by reference into the summary prospectus, making them legally a part of the summary prospectus.

Investment Objective

The fund’s goal is to track as closely as possible, before fees and expenses, the total return of an index composed of inflation-protected U.S. Treasury securities.

Fund Fees and Expenses

This 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 table and Example below.

Shareholder Fees (fees paid directly from your investment)
​	None

Annual Fund Operating Expenses (expenses that you pay each year as a % of the value of your investment)
Management fees	0.05
Other expenses	None
Total annual fund operating expenses	0.05

Example

This example is intended to help you compare the cost of investing in the fund with the cost of investing in other 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 time periods. The example also assumes that your investment has a 5% return each year and that the fund’s operating expenses remain the same. Your actual costs may be higher or lower.

Expenses on a $10,000 Investment
1 Year			3 Years			5 Years			10 Years
​	$	5	​	$	16	​	$	28	​	$	64

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 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 the 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 31% of the average value of its portfolio.

Principal Investment Strategies

To pursue its goal, the fund generally invests in securities that are included in the Bloomberg US Treasury Inflation-Linked Bond Index† (Series-L)SM. The index includes all publicly-issued treasury inflation-protected securities (TIPS) that have at least one year remaining to maturity, are rated investment grade and have $500 million or more of outstanding face value. The TIPS in the index must be denominated in U.S. dollars and must be fixed-rate and non-convertible. The index is market capitalization weighted and the TIPS in the index are updated on the last business day of each month. TIPS are publicly issued, dollar-denominated U.S. government securities issued by the U.S. Treasury that have principal and interest payments linked to an official inflation measure (as measured by the Consumer Price Index, or CPI) and their payments are supported by the full faith and credit of the United States.

It is the fund’s policy that, under normal circumstances, it will invest at least 90% of its net assets (including, for this purpose, any borrowings for investment purposes) in securities included in the index. The fund will notify its shareholders at least 60 days before changing this policy. The fund will generally seek to replicate

†

Index ownership – Bloomberg® and Bloomberg US Treasury Inflation-Linked Bond Index are service marks of Bloomberg Finance L.P. and its affiliates, including Bloomberg Index Services Limited (BISL), the administrator of the indices (collectively, “Bloomberg”). Bloomberg is not affiliated with Charles Schwab Investment Management, Inc.,dba Schwab Asset Management, and Bloomberg does not approve, endorse, review, or recommend Schwab Treasury Inflation Protected Securities Index Fund. Bloomberg does not guarantee the timeliness, accurateness, or completeness of any data or information relating to Schwab Treasury Inflation Protected Securities Index Fund.

Schwab Treasury Inflation Protected Securities Index Fund | Summary Prospectus1​

REG58795-41   00317369​

the performance of the index by giving the same weight to a given security as the index does. However, when the investment adviser believes it is in the best interest of the fund, such as to avoid purchasing odd-lots (i.e., purchasing less than the usual number of shares traded for a security), for tax considerations, or to address liquidity considerations with respect to a security, the investment adviser may cause the fund’s weighting of a security to be more or less than the index’s weighting of the security. The fund may sell securities that are represented in the index in anticipation of their removal from the index.

Under normal circumstances, the fund may invest up to 10% of its net assets in securities not included in the index. The principal types of these investments include those that the investment adviser believes will help the fund track the index, such as investments in (a) securities that are not represented in the index but the investment adviser anticipates will be added to the index; (b) high-quality liquid investments, such as securities issued by the U.S. government, its agencies or instrumentalities, including obligations that are not guaranteed by the U.S. Treasury, and obligations that are issued by private issuers that are guaranteed as to principal or interest by the U.S. government, its agencies or instrumentalities, and (c) investment companies. The fund may also invest in cash and cash equivalents, including money market funds, enter into repurchase agreements, and may lend its securities to minimize the difference in performance that naturally exists between an index fund and its corresponding index.

The investment adviser typically seeks to track the price and yield performance of the index by replicating the index. This means that the fund generally expects that it will hold the same securities as those included in the index. However, the investment adviser may use sampling techniques if the investment adviser believes such use will best help the fund to track the index or is otherwise in the best interest of the fund. Sampling techniques involve investing in a limited number of index securities that, when taken together, are expected to perform similarly to the index as a whole. These techniques are based on a variety of factors, including interest rate and yield curve risk, maturity exposures, and other risk factors and characteristics. When the fund uses sampling techniques, the fund generally expects that its yield, maturity and weighted average effective duration will be similar to those of the index.

Principal Risks

The fund is subject to risks, any of which could cause an investor to lose money. The fund’s principal risks include:

Market Risk. Financial markets rise and fall in response to a variety of factors, sometimes rapidly and unpredictably. Markets may be impacted by economic, political, regulatory and other conditions, including economic sanctions and other government actions. In addition, the occurrence of global events, such as war, terrorism, environmental disasters, natural disasters and epidemics, may also negatively affect the financial markets. As with any investment whose performance is tied to these markets, the value of an investment in the fund will fluctuate, which means that an investor could lose money over short or long periods.

Investment Style Risk. The fund is an index fund. Therefore, the fund follows the securities included in the index during upturns as well as downturns. Because of its indexing strategy, the fund does not take steps to reduce market exposure or to lessen the effects of a declining market. In addition, because of the fund’s expenses, the fund’s performance may be below that of the index. Errors relating to the index may occur from time to time and may not be identified by the index provider for a period of time. In addition, market disruptions could cause delays in the index’s rebalancing schedule. Such errors and/or market disruptions may result in losses for the fund.

Inflation-Protected Security Risk. The value of inflation-protected securities, including TIPS, generally will fluctuate in response to changes in “real” interest rates, generally decreasing when real interest rates rise and increasing when real interest rates fall. Real interest rates represent nominal (or stated) interest rates reduced by the expected impact of inflation. In addition, interest payments on inflation-indexed securities will generally vary up or down along with the rate of inflation.

Interest Rate Risk. Interest rates rise and fall over time. As with any investment whose yield reflects current interest rates, the fund’s yield will change over time. During periods when interest rates are low, the fund’s yield (and total return) also may be low. Changes or the anticipation of changes in interest rates also may affect the fund’s share price: a rise in interest rates generally causes the fund’s share price to fall. The longer the fund’s portfolio duration, the more sensitive to interest rate movements its share price is likely to be. Also, a change in a central bank’s monetary policy or economic conditions, among other things, may result in a change in interest rates, which could have sudden and unpredictable effects on the markets and significantly impact the value of fixed-income securities in which the fund invests. A sudden or unpredictable rise in interest rates may cause volatility and the value of fixed-income securities to decline.

Credit Risk. A decline in the credit quality of an issuer, guarantor or liquidity provider of a portfolio investment or a counterparty could cause the fund to lose money or underperform. The fund could lose money if, due to a decline in credit quality, the issuer, guarantor or liquidity provider of a portfolio investment or a counterparty fails to make, or is perceived as being unable or unwilling to make, timely principal or interest payments or otherwise honor its obligations.

Liquidity Risk. The fund may be unable to sell certain securities, such as illiquid securities, readily at a favorable time or price, or the fund may have to sell them at a loss.

Sampling Index Tracking Risk. To the extent the fund uses sampling techniques, the fund will not fully replicate the index and may hold securities not included in the index. As a result, the fund will be subject to the risk that the investment adviser’s investment management strategy, the implementation of which is subject to a number of constraints, may not produce the intended results. If the fund utilizes a sampling approach, it may not track the return of the index as well as it would if the fund purchased all of the securities in the index.

2Schwab Treasury Inflation Protected Securities Index Fund | Summary Prospectus

Tracking Error and Correlation Risk. As an index fund, the fund seeks to track the performance of the index, although it may not be successful in doing so. Further, there can be no guarantee that the fund will achieve a high degree of correlation between the fund’s performance and that of its index. The correlation between the performance of the fund and that of its index, positive or negative, is called “tracking error.” Tracking error can be caused by many factors and it may be significant.

Securities Lending Risk. Securities lending involves the risk of loss of rights in, or delay in recovery of, the loaned securities if the borrower fails to return the security loaned or becomes insolvent.

Money Market Fund Risk. The fund may invest in underlying money market funds that seek to maintain a stable $1.00 net asset value. Although an underlying money market fund seeks to maintain a stable $1.00 net asset value, it is possible to lose money by investing in such a money market fund. In addition, money market funds are not designed to offer capital appreciation. Certain underlying money market funds may impose a fee upon the sale of shares under certain circumstances.

For more information on the risks of investing in the fund, please see the “Fund Details” section in the prospectus.

Performance

The bar chart below shows how the fund’s investment results have varied from year to year, and the following table shows how the fund’s average annual total returns for various periods compared to that of one or more indices. The Bloomberg US Aggregate Bond Index serves as the fund’s regulatory index and provides a broad measure of market performance. The fund generally invests in securities that are included in the Bloomberg US Treasury Inflation-Linked Bond Index (Series-L). The fund does not seek to track the regulatory index. This information provides some indication of the risks of investing in the fund. All figures assume distributions were reinvested. Keep in mind that future performance (both before and after taxes) may differ from past performance. For current performance information, please see
www.schwabassetmanagement.com/prospectus.

Annual Total Returns (%) as of 12/31

Best Quarter: 4.45% Q4 2023

Worst Quarter: (6.05%) Q2 2022

Year-to-date performance (before taxes) as of 9/30/24: 5.03%

Average Annual Total Returns as of 12/31/23
​	1 Year		5 Years		10 Years
Before taxes	​	3.78%	​	3.04%	​	2.30%
After taxes on distributions	​	2.47%	​	1.53%	​	1.12%
After taxes on distributions and sale of shares	​	2.22%	​	1.73%	​	1.27%
Comparative Indices (reflect no deduction for fees, expenses, or taxes)	​	​	​	​	​	​
Bloomberg US Aggregate Bond Index	​	5.53%	​	1.10%	​	1.81%
Bloomberg US Treasury Inflation-Linked Bond Index (Series-L)	​	3.90%	​	3.15%	​	2.42%

The after-tax figures reflect the highest individual federal income tax rates in effect during the period and do not reflect the impact of state and local taxes. Your actual after-tax returns depend on your individual tax situation. In addition, after-tax returns are not relevant if you hold your fund shares through a tax-deferred arrangement, such as a 401(k) plan, an individual retirement account (IRA) or other tax-advantaged account. In some cases, the return after taxes on distributions and sale of shares may exceed the fund’s other returns due to an assumed benefit from any losses on a sale of shares at the end of the measurement period.

Investment Adviser

Charles Schwab Investment Management, Inc., dba Schwab Asset Management®

Portfolio Managers

Matthew Hastings, CFA, Managing Director and Head of Bond Index Strategies, is responsible for the day-to-day co-management of the fund. He has managed the fund since 2006.

Mark McKissick, CFA, Senior Portfolio Manager, is responsible for the day-to-day co-management of the fund. He has managed the fund since 2016.

Purchase and Sale of Fund Shares

The fund is open for business each day that the New York Stock Exchange (NYSE) is open. If the NYSE is closed due to weather or other extenuating circumstances on a day it would typically be open for business, or the NYSE has an unscheduled early closing on a day it has opened for business, the fund reserves the right to treat such day as a business day and accept purchase and redemption orders and calculate its share price as of the normally scheduled close of regular trading on the NYSE for that day.

Investors may only invest in the fund through an account at Charles Schwab & Co., Inc. (Schwab) or another financial intermediary. When you place orders to purchase, exchange or redeem fund shares through an account at Schwab or another financial intermediary, you must follow Schwab’s or the other financial intermediary’s transaction procedures.

There is no minimum initial investment for the fund.

Schwab Treasury Inflation Protected Securities Index Fund | Summary Prospectus3​

Tax Information

Dividends and capital gains distributions received from the fund will generally be taxable as ordinary income or capital gains, unless you are investing through an IRA, 401(k) or other tax-advantaged account (in which case you may be taxed later, upon withdrawal of your investment from such account).

Payments to Financial Intermediaries

If you purchase shares of the fund through a broker-dealer or other financial intermediary (such as a bank), the adviser 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 financial intermediary and your salesperson to recommend the fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

4Schwab Treasury Inflation Protected Securities Index Fund | Summary Prospectus