Strategy. The Portfolio is a fund of funds, which means that the Portfolio generally allocates its assets among other funds managed by Dimensional Fund Advisors LP (the Advisor), although it has the ability to invest directly in securities and derivatives. The Retirement Income Portfolio is designed for an investor currently in retirement. To achieve its investment objective, the Portfolio allocates its assets to other mutual funds managed by the Advisor (i.e., the Underlying Funds) according to an asset allocation strategy designed for investors who have retired and are planning to withdraw the value of the investment in the Portfolio over many years. The asset allocation strategy for the Portfolio reflects the need for reduced equity risk and lower volatility of the … Show more… The Portfolio is a fund of funds, which means that the Portfolio generally allocates its assets among other funds managed by Dimensional Fund Advisors LP (the Advisor), although it has the ability to invest directly in securities and derivatives. The Retirement Income Portfolio is designed for an investor currently in retirement. To achieve its investment objective, the Portfolio allocates its assets to other mutual funds managed by the Advisor (i.e., the Underlying Funds) according to an asset allocation strategy designed for investors who have retired and are planning to withdraw the value of the investment in the Portfolio over many years. The asset allocation strategy for the Portfolio reflects the need for reduced equity risk and lower volatility of the inflation-adjusted income the Portfolio may be able to support during an investors retirement. As of February 28, 2026, the Retirement Income Portfolio has a target allocation of 15% to 25% to equity Underlying Funds and a target allocation of approximately 75% to 85% to fixed income Underlying Funds, which may include exposure through those fixed income Underlying Funds to U.S. Treasury Inflation-Protected Securities (TIPS). As of February 28, 2026, the Portfolio may invest in: (1) domestic equity Underlying Funds that purchase a broad and diverse portfolio of securities of U.S. operating companies; (2) international equity Underlying Funds that purchase a broad and diverse portfolio of securities of companies in developed and emerging markets; and (3) fixed income Underlying Funds that may purchase U.S. and foreign debt securities such as obligations issued or guaranteed by the U.S. and foreign governments, their agencies and instrumentalities, long-, intermediate- and short-term TIPS, bank obligations, commercial paper, repurchase agreements, money market funds, obligations of other domestic and foreign issuers, securities of domestic and foreign issuers denominated in U.S. dollars but not trading in the United States, obligations of supranational organizations, and inflation-protected securities. The fixed income Underlying Funds primarily invest in securities that are considered investment grade at the time of purchase and which have a range of maturities, including ultra-short, intermediate, and long-term. Certain equity Underlying Funds purchase a broad and diverse group of securities of companies with a greater emphasis on smaller capitalization, lower relative price, and higher profitability companies as compared to their representation in the universe of securities such Underlying Funds invest in. A summary of the investment strategies and policies of the Underlying Funds in which the Portfolio invests as of the date of this Prospectus is described in the Portfolios Prospectus in the section entitled ADDITIONAL INFORMATION ON INVESTMENT OBJECTIVES AND POLICIES. The Retirement Income Portfolio and each Underlying Fund may purchase or sell futures contracts and options on futures contracts, to adjust market exposure based on actual or expected cash inflows to or outflows from the Portfolio or Underlying Fund. Certain Underlying Funds may enter into foreign currency exchange transactions, including foreign currency forward contracts, in connection with the settlement of foreign securities, to hedge foreign currency risks, to hedge against fluctuations in currency exchange rates or to transfer balances from one currency to another. Also, the Portfolio and the Underlying Funds may lend their portfolio securities to generate additional income. Show less