DFA Diversified Fixed Income Portfolio

SHARE CLASS (TICKER): INSTITUTIONAL CLASS (DFXIX)

Summary Prospectus

February 28, 2019

Before you invest, you may want to review the Portfolio’s Prospectus, which contains more information about the Portfolio and its risks. You can find the Portfolio’s Prospectus and other information about the Portfolio, including the Statement of Additional Information (SAI) and most recent reports to shareholders, when available, online at https://us.dimensional.com/fund-documents. You can also get this information at no cost by calling collect to (512) 306-7400 or by sending an e-mail request to document_requests@dimensional.com. The Portfolio’s Prospectus and SAI, both dated February 28, 2019, as may be supplemented, are incorporated by reference into this Summary Prospectus.

Beginning on January 1, 2021, as permitted by regulations adopted by the Securities and Exchange Commission, paper copies of the Portfolio’s annual and semi-annual shareholder reports will no longer be sent by mail, unless you specifically request paper copies of the reports from the Portfolio or from your financial intermediary. Instead, the reports will be made available on the Portfolio’s website, and you will be notified by mail each time a report is posted and provided with a website link to access the report.

If you already elected to receive shareholder reports electronically, you will not be affected by this change and you need not take any action. You may elect to receive shareholder reports and other communications electronically from the Portfolio anytime by contacting the Portfolio’s transfer agent at (888) 576-1167 or by contacting your financial intermediary.

You may elect to receive all future shareholder reports in paper free of charge. You can inform the Portfolio that you wish to continue receiving paper copies of your shareholder reports by contacting your financial intermediary or, if you invest directly with the Portfolio, by calling (888) 576-1167, to let the Portfolio know of your request. Your election to receive reports in paper will apply to all DFA Funds held directly or to all funds held through your financial intermediary.

Investment Objective

The investment objective of the DFA Diversified Fixed Income Portfolio (the “Diversified Fixed Income Portfolio” or the “Portfolio”) is to provide a market rate of return for a fixed income portfolio with low relative volatility of returns.

Fees and Expenses of the Portfolio

This table describes the fees and expenses you may pay if you buy and hold shares of the Diversified Fixed Income Portfolio.

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

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Management Fee	0.12%
Other Expenses	0.03%
Acquired Fund Fees and Expenses	0.11%
Total Annual Fund Operating Expenses	0.26%
Fee Waiver and/or Expense Reimbursement*	0.11%
Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement	0.15%

* Dimensional Fund Advisors LP (the “Advisor”) has agreed to waive certain fees and in certain instances, assume certain expenses of the Diversified Fixed Income Portfolio. The Fee Waiver and Expense Assumption Agreement for the Diversified Fixed Income Portfolio will remain in effect through February 28, 2020, and may only be terminated by the Fund’s Board of Directors prior to that date. Under certain circumstances, the Advisor retains the right to seek reimbursement for any fees previously waived and/or expenses previously assumed up to thirty-six months after such fee waiver and/or expense assumption.

EXAMPLE

This Example is meant to help you compare the cost of investing in the Diversified Fixed Income Portfolio with the cost of investing in other mutual funds. The Example assumes that you invest $10,000 in the Portfolio for the time periods indicated. The Example also assumes that your investment has a 5% return each year and that the Portfolio’s operating expenses remain the same. The costs for the Diversified Fixed Income Portfolio reflect the net expenses of the Portfolio that result from the contractual expense waiver in the first year only. 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
	$	15		$	73		$	135		$	320

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PORTFOLIO TURNOVER

A mutual fund generally 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 Portfolio shares are held in a taxable account. The Diversified Fixed Income Portfolio does not pay transactions costs when buying and selling shares of other mutual funds managed by the Advisor (the “Underlying Funds”); however, the Underlying Funds pay transaction costs when buying and selling securities for their portfolio and the Diversified Fixed Income Portfolio pays transaction costs when buying and selling securities directly. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Diversified Fixed Income Portfolio’s performance. During the most recent fiscal year, the Diversified Fixed Income Portfolio’s portfolio turnover rate was 3% of the average value of its direct investments portfolio.

Principal Investment Strategies

The investment objective of the Diversified Fixed Income Portfolio is to provide a market rate of return for a fixed income portfolio with low relative volatility of returns. The Portfolio seeks its investment objective by investing directly or through Underlying Funds in a universe of U.S. and foreign debt securities, including inflation-protected securities. The Portfolio and/or its Underlying Funds invest in obligations issued or guaranteed by the U.S. and foreign governments, their agencies and instrumentalities, corporate debt obligations, bank obligations, commercial paper, repurchase agreements, obligations of other domestic and foreign issuers, securities of domestic or foreign issuers denominated in U.S. dollars but not trading in the United States, and obligations of supranational organizations. The inflation-protected securities in which the Portfolio and/or its Underlying Funds invest may include Treasury Inflation-Protected Securities. As of the date of this Prospectus, the Portfolio invests a portion of its assets in the DFA Two-Year Global Fixed Income Portfolio and DFA Intermediate Government Fixed Income Portfolio and/or other Underlying Funds, but the Portfolio also invests a substantial portion of its assets directly.

Depending on the credit and term spreads in the current yield curves, the Diversified Fixed Income Portfolio will adjust its investment allocations to credit and maturity, within the eligible universe of investments held directly or through Underlying Funds. The fixed income securities in which the Portfolio invests will be considered investment grade at the time of purchase. Generally, the Portfolio will purchase debt securities that mature within twenty years from the date of settlement. The Portfolio will ordinarily have an average weighted maturity, based on market values, between two and seven years.

As a non-fundamental policy, under normal circumstances, the Diversified Fixed Income Portfolio will invest directly, or indirectly through its investment in the Underlying Funds, at least 80% of its net assets in fixed income securities. In

DFA Diversified Fixed Income Portfolio Summary Prospectus    3

addition, the Portfolio and each Underlying Fund are authorized to invest more than 25% of its total assets in U.S. Treasury bonds, bills and notes, and obligations of federal agencies and instrumentalities.

Because many of the Diversified Fixed Income Portfolio’s and certain Underlying Funds’ investments may be denominated in foreign currencies, the Portfolio and such Underlying Funds may also enter into foreign currency forward contracts to attempt to protect against uncertainty in the level of future foreign currency rates, to hedge against fluctuations in currency exchange rates or to transfer balances from one currency to another. In regard to currency hedging, it is generally not possible to precisely match the foreign currency exposure of such foreign currency forward contracts to the value of the securities involved due to fluctuations in the market values of such securities and cash flows into and out of the Portfolio or Underlying Fund between the date a foreign currency forward contract is entered into and the date it expires. The Portfolio and certain Underlying Funds may also purchase or sell futures contracts and options on futures contracts for securities and indices, to hedge their currency exposure or to adjust market exposure based on actual or expected cash inflows to or outflows from the Portfolio or Underlying Fund. The Portfolio does not intend to sell futures contracts to establish short positions in individual securities or to use derivatives for purposes of speculation or leveraging investment returns.

The Diversified Fixed Income Portfolio and the Underlying Funds may lend their portfolio securities to generate additional income.

Principal Risks

Because the value of your investment in the Portfolio will fluctuate, there is the risk that you will lose money. An investment in the Portfolio is not a deposit of a bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency. The following is a description of principal risks of investing in the Portfolio.

Fund of Funds Risk: The investment performance of the Diversified Fixed Income Portfolio is affected by the investment performance of the Underlying Funds in which the Portfolio invests. The ability of the Portfolio to achieve its investment objective depends on the ability of the Underlying Funds to meet their investment objectives and on the Advisor’s decisions regarding the allocation of the Portfolio’s assets among Underlying Funds. There can be no assurance that the investment objective of the Portfolio or any Underlying Fund will be achieved. Through its investments in the Underlying Funds, the Portfolio is subject to the risks of the Underlying Funds’ investments. When the Portfolio invests in Underlying Funds, investors are exposed to a proportionate share of the expenses of those Underlying Funds in addition to the expenses of the Portfolio. The risks of the Diversified Fixed Income Portfolio’s and Underlying Funds’ investments are described below.

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Market Risk: Even a long-term investment approach cannot guarantee a profit. Economic, political, and issuer specific events will cause the value of securities, and the Portfolio that owns them, to rise or fall.

Foreign Securities and Currencies Risk: Foreign securities prices may decline or fluctuate because of: (a) economic or political actions of foreign governments, and/or (b) less regulated or liquid securities markets. Investors holding these securities may also be exposed to foreign currency risk (the possibility that foreign currency will fluctuate in value against the U.S. dollar or that a foreign government will convert, or be forced to convert, its currency to another currency, changing its value against the U.S. dollar). The Portfolio hedges foreign currency risk.

Foreign Government Debt Risk: The risk that: (a) the governmental entity that controls the repayment of government debt may not be willing or able to repay the principal and/or to pay the interest when it becomes due, due to factors such as political considerations, the relative size of the governmental entity’s debt position in relation to the economy, cash flow problems, insufficient foreign currency reserves, the failure to put in place economic reforms required by the International Monetary Fund or other multilateral agencies, and/or other national economic factors; (b) governments may default on their debt securities, which may require holders of such securities to participate in debt rescheduling; and (c) there is no legal or bankruptcy process by which defaulted government debt may be collected in whole or in part.

Interest Rate Risk: Fixed income securities are subject to interest rate risk because the prices of fixed income securities tend to move in the opposite direction of interest rates. When interest rates rise, fixed income security prices fall. When interest rates fall, fixed income security prices rise. In general, fixed income securities with longer maturities are more sensitive to changes in interest rates.

Liquidity Risk: Liquidity risk exists when particular portfolio investments are difficult to purchase or sell. To the extent that the Portfolio holds illiquid investments, the Portfolio’s performance may be reduced due to an inability to sell the investments at opportune prices or times. Liquid portfolio investments may become illiquid or less liquid after purchase by the Portfolio due to low trading volume, adverse investor perceptions and/or other market developments. Liquidity risk includes the risk that the Portfolio will experience significant net redemptions at a time when it cannot find willing buyers for its portfolio securities or can only sell its portfolio securities at a material loss. Liquidity risk can be more pronounced in periods of market turmoil.

Inflation-Protected Securities Interest Rate Risk: Inflation-protected securities may react differently from other fixed income securities to changes in interest rates. Because interest rates on inflation-protected securities are adjusted for inflation, the values of these securities are not materially affected by inflation expectations. Therefore, the value of inflation-protected securities are anticipated to change in response to changes in “real” interest rates, which represent nominal

DFA Diversified Fixed Income Portfolio Summary Prospectus    5

(stated) interest rates reduced by the expected impact of inflation. Generally, the value of an inflation-protected security will fall when real interest rates rise and will rise when real interest rates fall.

Inflation-Protected Securities Tax Risk: Any increase in the principal amount of an inflation-protected security may be included for tax purposes in the Portfolio’s gross income, even though no cash attributable to such gross income has been received by the Portfolio. In such event, the Portfolio may be required to make annual gross distributions to shareholders that exceed the cash it has otherwise received. In order to pay such distributions, the Portfolio may be required to raise cash by selling its investments. The sale of such investments could result in capital gains to the Portfolio and additional capital gain distributions to shareholders. In addition, adjustments during the taxable year for deflation to an inflation-indexed bond held by the Portfolio may cause amounts previously distributed to shareholders in the taxable year as income to be characterized as a return of capital.

Risks of Investing for Inflation Protection: Because the interest and/or principal payments on an inflation-protected security are adjusted periodically for changes in inflation, the income distributed by the Portfolio may be irregular. Although the U.S. Treasury guarantees to pay at least the original face value of any inflation-protected securities the Treasury issues, other issuers may not offer the same guarantee. Also, inflation-protected securities, including those issued by the U.S. Treasury, are not protected against deflation. As a result, in a period of deflation, the inflation-protected securities held by the Portfolio may not pay any income and the Portfolio may suffer a loss during such periods. While inflation-protected securities are expected to be protected from long-term inflationary trends, short-term increases in inflation may lead to a decline in the Portfolio’s value. If interest rates rise due to reasons other than inflation, the Portfolio’s investment in these securities may not be protected to the extent that the increase is not reflected in the securities’ inflation measures. In addition, positive adjustments to principal generally will result in taxable income to the Portfolio at the time of such adjustments (which generally would be distributed by the Portfolio as part of its taxable dividends), even though the principal amount is not paid until maturity. The current market value of inflation-protected securities is not guaranteed and will fluctuate.

Credit Risk: Credit risk is the risk that the issuer of a security may be unable to make interest payments and/or repay principal when due. A downgrade to an issuer’s credit rating or a perceived change in an issuer’s financial strength may affect a security’s value, and thus, impact the Portfolio’s performance. Government agency obligations have different levels of credit support and, therefore, different degrees of credit risk. Securities issued by agencies and instrumentalities of the U.S. Government that are supported by the full faith and credit of the United States, such as the Federal Housing Administration and Ginnie Mae, present little credit risk. Other securities issued by agencies and instrumentalities sponsored by the U.S. Government, that are supported only by the issuer’s right to borrow from the U.S. Treasury, subject to certain limitations, and securities issued by agencies and instrumentalities sponsored by the U.S. Government that are sponsored by

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the credit of the issuing agencies, such as Freddie Mac and Fannie Mae, are subject to a greater degree of credit risk. U.S. government agency securities issued or guaranteed by the credit of the agency may still involve a risk of non-payment of principal and/or interest.

Income Risk: Income risk is the risk that falling interest rates will cause the Portfolio’s income to decline because, among other reasons, the proceeds from maturing short-term securities in its portfolio may be reinvested in lower-yielding securities.

Derivatives Risk: Derivatives are instruments, such as futures, and options thereon, and foreign currency forward contracts, whose value is derived from that of other assets, rates or indices. Derivatives can be used for hedging (attempting to reduce risk by offsetting one investment position with another) or non-hedging purposes. Hedging with derivatives may increase expenses, and there is no guarantee that a hedging strategy will work. While hedging can reduce or eliminate losses, it can also reduce or eliminate gains or cause losses if the market moves in a manner different from that anticipated by the Portfolio or if the cost of the derivative outweighs the benefit of the hedge. The use of derivatives for non-hedging purposes may be considered to carry more risk than other types of investments. When the Portfolio uses derivatives, the Portfolio will be directly exposed to the risks of those derivatives. Derivative instruments are subject to a number of risks including counterparty, liquidity, interest rate, market, credit and management risks, as well as the risk of improper valuation. Changes in the value of a derivative may not correlate perfectly with the underlying asset, rate or index, and the Portfolio could lose more than the principal amount invested.

Securities Lending Risk: Securities lending involves the risk that the borrower may fail to return the securities in a timely manner or at all. As a result, the Diversified Fixed Income Portfolio may lose money and there may be a delay in recovering the loaned securities. The Portfolio could also lose money if it does not recover the securities and/or the value of the collateral falls, including the value of investments made with cash collateral. Securities lending also may have certain adverse tax consequences.

Cyber Security Risk: The Portfolio’s and its service providers’ use of internet, technology and information systems may expose the Portfolio to potential risks linked to cyber security breaches of those technological or information systems. Cyber security breaches, amongst other things, could allow an unauthorized party to gain access to proprietary information, customer data, or fund assets, or cause the Portfolio and/or its service providers to suffer data corruption or lose operational functionality.

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Performance

The bar chart and table immediately following illustrate the variability of the Diversified Fixed Income Portfolio’s returns and are meant to provide some indication of the risks of investing in the Portfolio. The bar chart shows the changes in the Diversified Fixed Income Portfolio’s performance from year to year. The table illustrates how annualized one year and since inception returns, both before and after taxes, compare with those of a broad measure of market performance. The Diversified Fixed Income Portfolio’s past performance (before and after taxes) is not an indication of future results. Updated performance information for the Portfolio can be obtained by visiting http://us.dimensional.com.

The after-tax returns presented in the table for the Diversified Fixed Income Portfolio 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 in the table. In addition, the after-tax returns shown are not relevant to investors who hold shares of the Portfolio through tax-advantaged arrangements, such as 401(k) plans or individual retirement accounts.

DFA Diversified Fixed Income Portfolio Institutional Class Shares—Total Returns

January 2017-December 2018
Highest Quarter	Lowest Quarter
1.70% (10/18–12/18)	-0.76% (1/18–3/18)

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Annualized Returns (%)

Periods ending December 31, 2018

	1 Year			Since 08/10/16 Inception
DFA Diversified Fixed Income Portfolio
Return Before Taxes		1.07	%		0.10	%
Return After Taxes on Distributions		0.21	%		-0.71	%
Return After Taxes on Distributions and Sale of Portfolio Shares		0.63	%		-0.28	%
Bloomberg Barclays U.S. Intermediate Government Bond Index (reflects no deduction for fees, expenses, or taxes on sales)		1.43	%		0.08	%

Investment Advisor/Portfolio Management

Dimensional Fund Advisors LP serves as the investment advisor for the Diversified Fixed Income Portfolio. Dimensional Fund Advisors Ltd. and DFA Australia Limited serve as the sub-advisors for the Diversified Fixed Income Portfolio. The following individuals are responsible for coordinating the day-to-day management of the Diversified Fixed Income Portfolio:

• David A. Plecha, Senior Portfolio Manager and Vice President of the Advisor, has been a portfolio manager of the Portfolio since inception (2016).

• Joseph F. Kolerich, Senior Portfolio Manager and Vice President of the Advisor, has been a portfolio manager of the Portfolio since inception (2016).

Purchase and Redemption of Fund Shares

Investors may purchase or redeem shares of the Diversified Fixed Income Portfolio on each day that the NYSE is scheduled to be open for business by first contacting the Portfolio’s transfer agent at (888) 576-1167. Shareholders that invest in the Portfolio through a financial intermediary should contact their financial intermediary regarding purchase and redemption procedures. The Portfolio generally is available for investment only by institutional clients, clients of registered investment advisors, clients of financial institutions and a limited number of certain other investors as approved from time to time by the Advisor. All investments are subject to approval of the Advisor.

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Tax Information

The dividends and distributions you receive from the Diversified Fixed Income Portfolio are taxable and generally will be taxed as ordinary income, capital gains, or some combination of both, unless you are investing through a tax-advantaged arrangement, such as a 401(k) plan or an individual retirement account, in which case distributions may be taxed as ordinary income when withdrawn from the plan or account.

Payments to Financial Intermediaries

If you purchase the Portfolio through a broker-dealer or other financial intermediary (such as a bank), the Portfolio and its related companies may pay the intermediary for the sale of the Portfolio shares and/or related services. These payments may create a conflict of interest by influencing the financial intermediary to recommend the Portfolio over another investment. Ask your financial advisor or visit your financial intermediary’s website for more information.

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