Strategy. To pursue its goal, the fund generally invests in securities that are included in the Bloomberg US Aggregate Bond Index . The index is a broad-based benchmark measuring the performance of the U.S. investment grade, taxable bond market, including U.S. Treasuries, government-related and corporate bonds, mortgage pass-through securities, commercial mortgage-backed securities, and asset-backed securities that are publicly available for sale in the United States. To be eligible for inclusion in the index, a security must be fixed rate, non-convertible, U.S. dollar-denominated and have one or more years remaining to maturity. The index excludes certain types of securities, including, bonds with equity type features (e.g., warrants, convertibles and preferreds), tax-exempt municipal securities, inflation-linked bonds, floating-rate bonds, strips, private placements, U.S. dollar-denominated … Show more… To pursue its goal, the fund generally invests in securities that are included in the Bloomberg US Aggregate Bond Index . The index is a broad-based benchmark measuring the performance of the U.S. investment grade, taxable bond market, including U.S. Treasuries, government-related and corporate bonds, mortgage pass-through securities, commercial mortgage-backed securities, and asset-backed securities that are publicly available for sale in the United States. To be eligible for inclusion in the index, a security must be fixed rate, non-convertible, U.S. dollar-denominated and have one or more years remaining to maturity. The index excludes certain types of securities, including, bonds with equity type features (e.g., warrants, convertibles and preferreds), tax-exempt municipal securities, inflation-linked bonds, floating-rate bonds, strips, private placements, U.S. dollar-denominated 25 and 50 par retail bonds, structured notes and pass-through certificates. The index is market capitalization weighted and the securities in the index are updated on the last business day of each month. It is the funds 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, including TBA transactions, as defined below. The fund will notify its shareholders at least 60 days before changing this policy. Under normal circumstances, the fund may invest up to 10% of its net assets in securities not included in its 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; (c) other investment companies; and (d) derivatives, principally futures contracts. The fund may use futures contracts and other derivatives primarily to help manage interest rate, and credit risk exposure. The fund may also invest in cash and cash equivalents, including money market funds, and lend its securities to minimize the difference in performance that naturally exists between an index fund and its corresponding index. Because it is not possible or practical to purchase all of the securities in the index, the funds investment adviser will seek to track the total return of the index by using sampling techniques. 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, industry, sector and issuer weights, credit quality, and Index ownership Bloomberg and Bloomberg US Aggregate 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 U.S. Aggregate Bond Index Fund. Bloomberg does not guarantee the timeliness, accurateness, or completeness of any data or information relating to Schwab U.S. Aggregate Bond Index Fund. ? other risk factors and characteristics. The fund expects that its portfolio will hold less than the total number of securities in the index, but reserves the right to hold as many securities as it believes necessary to achieve the funds investment objective. The fund may sell securities that are represented in the index in anticipation of their removal from the index. The fund generally expects that its duration will closely correspond to the duration of the index, which as of August 31, 2025, was approximately 5.94 years. As of August 31, 2025, approximately 24.46% of the bonds represented in the index were U.S. fixed-rate agency mortgage pass-through securities. U.S. fixed-rate agency mortgage pass-through securities are securities issued by entities such as the Government National Mortgage Association (Ginnie Mae), the Federal National Mortgage Association (Fannie Mae), and the Federal Home Loan Mortgage Corporation (Freddie Mac) that are backed by pools of mortgages. Many transactions in fixed-rate mortgage pass-through securities occur through standardized contracts for future delivery in which the exact mortgage pools to be delivered are not specified until a few days prior to settlement, and are often referred to as to-be-announced transactions or TBA transactions. In a TBA transaction, the buyer and seller agree upon general trade parameters such as agency, settlement date, par amount and price. The actual pools delivered generally are determined two days prior to settlement date; however, it is not anticipated that the fund will receive the pools, but will instead participate in rolling TBA transactions. The fund anticipates that it may enter into such contracts on a regular basis. This may result in a significantly higher portfolio turnover for the fund than a typical index fund. The fund, pending settlement of such contracts, will invest its assets in high-quality liquid short-term instruments, including Treasury securities and shares of money market mutual funds. The fund will assume its pro rata share of the fees and expenses of any money market fund that it may invest in, in addition to the funds own fees and expenses. The fund will concentrate its investments (i.e., hold more than 25% of its total assets) in a particular industry, group of industries or sector to approximately the same extent that its index is so concentrated. For purposes of this limitation, securities of the U.S. government (including its agencies and instrumentalities), and repurchase agreements collateralized by U.S. government securities are not considered to be issued by members of any industry. Show less