DFA Investment Dimensions Group Inc.

11/15/2024 | Press release | Distributed by Public on 11/15/2024 13:45

Summary Prospectus by Investment Company - Form 497K

Dimensional VIT Inflation-Protected Securities Portfolio
(formerly, VIT Inflation-Protected Securities Portfolio)

SHARE CLASS: INSTITUTIONAL CLASS

Summary Prospectus

November 15, 2024

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://www.dimensional.com/us-en/document-center. You can also get this information at no cost by calling collect to (512) 306-7400 or by sending an e-mail request to [email protected]. The Portfolio's Prospectus and SAI, both dated February 28, 2024, as may be supplemented, are incorporated by reference into this Summary Prospectus. Shares of the Portfolio are sold only to insurance company separate accounts or to other investment companies funded by insurance company separate accounts. This Summary Prospectus is not intended for use by other investors.

Investment Objective

The investment objective of the Dimensional VIT Inflation-Protected Securities Portfolio ("Inflation-Protected Portfolio" or, the "Portfolio") is to provide inflation protection and earn current income consistent with inflation-protected securities.

Fees and Expenses of the Portfolio

This table describes the fees and expenses you may pay if you buy, hold or sell shares of the Portfolio. The expenses in the table do not include any fees or charges imposed by the variable insurance contract. If such fees and charges were included, the expenses would be higher.

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

0.09%

Other Expenses

0.02%

Total Annual Fund Operating Expenses

0.11%

EXAMPLE

This Example is meant to help you compare the cost of investing in the Portfolio with the cost of investing in other funds. The Example does not include any fees or charges imposed by the variable insurance contract and if such fees were included, expenses would be higher. 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. Although your actual costs may be higher or lower, based on these assumptions your costs whether you redeem or hold your shares would be:

1 Year

3 Years

5 Years

10 Years

$11

$35

$62

$141

PORTFOLIO TURNOVER

A 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. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Portfolio's performance. During the

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most recent fiscal year, the Portfolio's portfolio turnover rate was 22% of the average value of its investment portfolio.

Principal Investment Strategies

The Inflation-Protected Portfolio seeks its investment objective by investing in a universe of inflation-protected securities that are structured to provide returns linked to the rate of inflation over the long-term. The Portfolio ordinarily invests in inflation-protected securities issued by the U.S. Government and its agencies and instrumentalities and the credit quality of such inflation-protected securities will be that of such applicable U.S. government, agency or instrumentality issuer.

As a non-fundamental policy, under normal circumstances, the Inflation-Protected Portfolio will invest at least 80% of its net assets in inflation-protected securities. Inflation-protected securities (also known as inflation-indexed securities) are securities whose principal and/or interest payments are adjusted for inflation, unlike conventional debt securities that make fixed principal and interest payments. Inflation-protected securities include Treasury Inflation-Protected Securities ("TIPS"), which are securities issued by the U.S. Treasury. The principal value of TIPS is adjusted for inflation (payable at maturity) and the semi-annual interest payments by TIPS equal a fixed percentage of the inflation-adjusted principal amount. These inflation adjustments are based upon the Consumer Price Index for Urban Consumers (CPI-U). The original principal value of TIPS is guaranteed. At maturity, TIPS are redeemed at the greater of their inflation-adjusted principal or par amount at original issue. Other types of inflation-protected securities may use other methods to adjust for inflation and other measures of inflation. In addition, inflation-protected securities issued by entities other than the U.S. Treasury may not provide a guarantee of principal value at maturity.

Generally, the Inflation-Protected Portfolio will purchase inflation-protected securities with maturities of between five and twenty years from the date of settlement, although at times, the Portfolio may purchase securities outside of this range. Under normal circumstances, when determining its duration, the Portfolio will consider a weighted average duration similar to the Bloomberg U.S. TIPS Index, which was approximately 6.57 years as of December 31, 2023. Duration is a measure of the sensitivity of a security's price to changes in interest rates. The longer a security's duration, the more sensitive it will be to changes in interest rates.

The Inflation-Protected Portfolio is authorized to invest more than 25% of its total assets in Treasury bonds, bills and notes and obligations of U.S. government agencies and instrumentalities. The Portfolio may also invest in money market funds. The Portfolio will not shift the maturity of its investments in anticipation of interest rate movements.

The Inflation-Protected Portfolio may purchase or sell futures contracts and options on futures contracts, to hedge its interest rate exposure or for non-hedging purposes,

Dimensional VIT Inflation-Protected Securities Portfolio

3

such as a substitute for direct investment or to increase or decrease market exposure based on actual or expected cash inflows to or outflows from the Portfolio.

The Inflation-Protected Portfolio may lend its 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.

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 a fund that owns them, to rise or fall.

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. During periods of very low or negative interest rates, a fund may be subject to a greater risk of rising interest rates. 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.

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 (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.

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 performance of a fund holding such securities. 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

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U.S. Treasury, subject to certain limitations, and securities issued by agencies and instrumentalities sponsored by the U.S. Government that are sponsored by 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.

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 a fund investing in such securities may be irregular. Although the U.S. Treasury guarantees to pay at maturity at least the original face value of any inflation-protected securities the Treasury issues, other issuers may not offer the same guarantee. Inflation-protected securities are not protected against deflation. As a result, in a period of deflation, the principal and income of inflation-protected securities held by a fund will decline and the fund 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 value of a fund holding such securities. For example, if interest rates rise due to reasons other than inflation, a fund'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 a fund at the time of such adjustments (which generally would be distributed by the fund 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.

Income Risk: Income risk is the risk that falling interest rates will cause a fund'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 contracts, and options thereon, 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 a fund 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 a fund uses derivatives, the fund will be directly exposed to the risks of those derivatives. Derivative instruments are subject to a number of risks including counterparty, settlement, 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 a fund could lose more than the principal amount invested.

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Liquidity Risk: Liquidity risk exists when particular portfolio investments are difficult to purchase or sell. To the extent that a fund holds illiquid investments, the fund'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 a fund due to low trading volume, adverse investor perceptions and/or other market developments. Liquidity risk includes the risk that a fund 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 or at increased costs. Liquidity risk can be more pronounced in periods of market turmoil or in situations where ownership of shares of a fund are concentrated in one or a few investors.

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, a fund may lose money and there may be a delay in recovering the loaned securities. A fund 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.

Operational Risk: Operational risks include human error, changes in personnel, system changes, faults in communication, and failures in systems, technology, or processes. Various operational events or circumstances are outside a fund's or its advisor's control, including instances at third parties. A fund and its advisor seek to reduce these operational risks through controls and procedures. However, measures that seek to reduce these operational risks through controls and procedures may not address every possible risk and may be inadequate to address these risks.

Cyber Security Risk: A fund and its service providers' use of internet, technology and information systems may expose the fund 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 fund and/or its service providers to suffer data corruption or lose operational functionality.

Performance

The bar chart and table immediately following illustrate the variability of the 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 Portfolio's performance from year to year. The performance reflected in the bar chart for the Portfolio does not reflect any insurance company separate account charges, which if reflected would lower returns. The table illustrates how annualized returns for certain periods, both before and after taxes, compare with those of a broad measure of market performance. The 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 https://www.dimensional.com/us-en/funds.

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The after-tax returns presented in the table for the 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.

Dimensional VIT Inflation-Protected Securities Portfolio Institutional Class Shares -Total Returns

January 2016-December 2023

Highest Quarter

Lowest Quarter

4.89% 2016, Q1

-6.40% 2022, Q2

Annualized Returns (%)
Periods ended December 31, 2023

Since

1 Year

5 Years

Inception

Dimensional VIT Inflation-Protected Securities Portfolio

Return Before Taxes

4.02%

3.10%

2.11%

1

Return After Taxes on Distributions

2.38%

1.38%

0.80%

1

Return After Taxes on Distributions and Sale of Portfolio Shares

2.37%

1.71%

1.08%

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Bloomberg U.S. TIPS Index

(reflects no deduction for fees, expenses or taxes on sales)

3.90%

3.15%

2.24%

1

1.

Since inception May 29, 2015.

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Investment Advisor/Portfolio Management

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

• Joseph F. Kolerich, Head of Fixed Income, Americas, member of the Investment Committee, Vice President, and Senior Portfolio Manager of the Advisor, has been a portfolio manager of the Portfolio since inception (2015).

• David A. Plecha, Global Head of Fixed Income Portfolio Management, member of the Investment Committee, Vice President, and Senior Portfolio Manager of the Advisor, has been a portfolio manager of the Portfolio since inception (2015).

• Alan R. Hutchison, Vice President and Senior Portfolio Manager of the Advisor, has been a portfolio manager of the Portfolio since 2016.

Purchase and Redemption of Fund Shares

Shares of the Portfolio are sold only to insurance company separate accounts funding variable life insurance contracts. Purchases and redemptions of shares of the Portfolio by a separate account will be effected at the net asset value per share. Contract owners do not deal directly with the Portfolio with respect to the acquisition or redemption of shares of the Portfolio. Please see the prospectus of the insurance company separate account for information regarding the purchase and redemption of shares of the Portfolio.

Tax Information

The dividends and distributions paid from the Portfolio to the insurance company separate accounts generally will consist of ordinary income, capital gains, or some combination of both. Because shares of the Portfolio must be purchased through separate accounts, such distributions will be exempt from current taxation by contract holders if left to accumulate within the separate account, in which case distributions generally will be taxed as ordinary income when withdrawn from the account.

Payments to Insurance Companies and Financial Intermediaries

The Portfolio and its related companies may make payments to an insurance company (and/or its related companies) in connection with the sale of Portfolio shares and/or related services. These payments to insurance companies that include the Portfolio as an underlying investment in a variable insurance contract could create a conflict of interest for the insurance companies. Such insurance companies (or their related companies) may pay a broker-dealer or other financial intermediary (such as a bank), for the sale of the Portfolio shares and/or related services. When received by a

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broker-dealer or other financial intermediary from an insurance company (or its related companies), such payments may create a conflict of interest by influencing the financial intermediary to recommend the Portfolio over another investment. Ask your financial advisor, visit your financial intermediary's website or see the prospectus of the insurance company separate account for more information.

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Dimensional Fund Advisors LP
6300 Bee Cave Road, Building One
Austin, TX 78746
(512) 306-7400

COMM-022824-004-8

00295880