DFA Investment Dimensions Group Inc.

11/15/2024 | Press release | Distributed by Public on 11/15/2024 13:46

Summary Prospectus by Investment Company - Form 497K

Dimensional VA Global Moderate Allocation Portfolio
(formerly, VA Global Moderate Allocation 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 VA Global Moderate Allocation Portfolio ("VA Global Moderate Allocation Portfolio" or, the "Portfolio") is to seek total return consisting of capital appreciation and current income.

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

0.23%

Other Expenses

0.01%

Acquired Fund Fees & Expenses

0.20%

Total Annual Fund Operating Expenses

0.44%

Fee Waiver and/or Expense Reimbursement1

0.16%

Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement

0.28%

1

Dimensional Fund Advisors LP (the "Advisor") has agreed to waive certain fees and in certain instances, assume certain expenses of the Portfolio. The Fee Waiver and/or Expense Assumption Agreement for the Portfolio will remain in effect through February 28, 2025, 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 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. The costs for the Portfolio reflect the net expenses of the Portfolio that result from the contractual expense waiver in the first year only. Although your

2

Dimensional Fund Advisors

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

$29

$125

$230

$539

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. The Portfolio does not pay transaction costs when buying and selling shares of other funds managed by the Advisor (the "Underlying Funds"); however, the Underlying Funds pay transaction costs when buying and selling securities for their portfolio. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Portfolio's performance. During the most recent fiscal year, the Portfolio's portfolio turnover rate was 24% based on the weighted average portfolio turnover ratios of each of the Portfolio's underlying investments.

Principal Investment Strategies

The VA Global Moderate Allocation Portfolio is a "fund of funds", which means that the Portfolio generally allocates its assets among other funds managed by the Advisor, although it has the ability to invest directly in securities and derivatives. To achieve the Portfolio's and the Underlying Funds' investment objectives, the Advisor implements an integrated investment approach that combines research, portfolio design, portfolio management, and trading functions. As further described below, the Portfolio's and the Underlying Funds' designs emphasize long-term drivers of expected returns identified by the Advisor's research, while balancing risk through broad diversification across companies and sectors. The Advisor's portfolio management and trading processes further balance those long-term drivers of expected returns with shorter-term drivers of expected returns and trading costs.

The VA Global Moderate Allocation Portfolio, under normal market circumstances, purchases shares of the Underlying Funds to achieve a moderate allocation to both global equity and global fixed income securities. Generally, the Portfolio invests its assets in domestic and international equity Underlying Funds and fixed income Underlying Funds to achieve an allocation that provides a moderate allocation to global equity securities, with an allocation of approximately 55% to 75% of the Portfolio's assets to domestic and international equity Underlying Funds and 25% to 45% of its assets to fixed income Underlying Funds. Periodically, the Advisor will review the allocations for the Portfolio in each Underlying Fund and may adjust allocations to Underlying Funds or may add or remove Underlying Funds in the Portfolio without notice to shareholders.

Dimensional VA Global Moderate Allocation Portfolio

3

In addition to its allocation strategy of providing exposure to the domestic and international equity and fixed income markets through investment in the Underlying Funds, the VA Global Moderate Allocation Portfolio further diversifies its investment portfolio by allocating its assets among Underlying Funds that represent a variety of different asset classes. As of the date of this Prospectus, the Portfolio invests in: (1) domestic equity Underlying Funds that purchase a broad and diverse portfolio of securities of U.S. operating companies of all market capitalization sizes with an emphasis on smaller, lower relative price, and higher profitability companies and a domestic equity Underlying Fund that primarily invests in publicly traded real estate investment trusts ("REITs"); (2) international equity Underlying Funds that purchase a broad and diverse portfolio of securities of companies in developed ex U.S. and emerging markets of all market capitalization sizes which may include frontier markets (emerging market countries in an earlier stage of development) with an emphasis on smaller, lower relative price, and higher profitability companies and an international equity Underlying Fund that primarily invests in publicly traded REITs and REIT-like entities; 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, corporate debt obligations, bank obligations, commercial paper, repurchase agreements, money market funds, 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 Advisor may also increase or reduce the VA Global Moderate Allocation Portfolio's and/or Underlying Funds' exposure to an eligible company, or exclude a company, based on shorter-term considerations, such as a company's price momentum, short-run reversals, and investment characteristics. In assessing a company's investment characteristics, the Advisor considers ratios such as recent changes in assets divided by total assets. The criteria the Advisor uses for assessing a company's investment characteristics are subject to change from time to time. In addition, the Advisor seeks to reduce trading costs using a flexible trading approach that looks for opportunities to participate in the available market liquidity, while managing turnover and explicit transaction costs.

The VA Global Moderate Allocation Portfolio and each Underlying Fund may purchase or sell futures contracts and options on futures contracts, to increase or decrease 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 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.

Certain fixed income Underlying Funds also may purchase or sell futures contracts and options on futures contracts, to hedge their interest rate or currency exposure or for non-hedging purposes, such as a substitute for direct investment. Also the

4

Dimensional Fund Advisors

Portfolio and Underlying Funds may lend their portfolio securities to generate additional income.

Certain of the Underlying Funds are available for investment only by insurance company separate accounts that fund variable life and variable annuity contracts.

A summary of the investment strategies and policies of the Underlying Funds in which the VA Global Moderate Allocation Portfolio invests as of the date of this Prospectus is described in the Portfolio's Prospectus in the section entitled "ADDITIONAL INFORMATION ON INVESTMENT OBJECTIVES AND POLICIES-Investments in Underlying Funds."

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 a fund of funds is affected by the investment performance of the underlying funds in which the fund of funds invests. The ability of a fund of funds 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 a fund of funds' assets among the underlying funds. A fund of funds may allocate assets to an underlying fund or asset class that underperforms other funds or asset classes. There can be no assurance that the investment objective of a fund of funds or any underlying fund will be achieved. Through its investments in the underlying funds, a fund of funds is subject to the risks of the underlying funds' investments. When a fund of funds invests in underlying funds, investors are exposed to a proportionate share of the expenses of those underlying funds in addition to the expenses of a fund of funds. Certain risks of the Underlying Funds' investments that are principal risks of investing in the Portfolio are described below.

Equity Market Risk: Even a long-term investment approach cannot guarantee a profit. Economic, market, political, and issuer-specific conditions and events will cause the value of equity securities, and a fund that owns them, to rise or fall. Stock markets are volatile, with periods of rising prices and periods of falling prices.

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.

Foreign Securities and Currencies Risk: Foreign securities prices may decline or fluctuate because of: (a) economic or political actions of foreign governments, and/or

Dimensional VA Global Moderate Allocation Portfolio

5

(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).

Depositary receipts are generally subject to the same risks as the foreign securities that they evidence or into which they may be converted. In addition, the underlying issuers of certain depositary receipts, particularly unsponsored or unregistered depositary receipts, are under no obligation to distribute shareholder communications to the holders of such receipts, or to pass through to them any voting rights with respect to the deposited securities. Depositary receipts that are not sponsored by the issuer may be less liquid and there may be less readily available public information about the issuer.

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.

Profitability Investment Risk: High relative profitability stocks may perform differently from the market as a whole and an investment strategy purchasing these securities may cause a fund to at times underperform equity funds that use other investment strategies.

Value Investment Risk: Value stocks may perform differently from the market as a whole and an investment strategy purchasing these securities may cause a fund to at times underperform equity funds that use other investment strategies. Value stocks can react differently to political, economic, and industry developments than the market as a whole and other types of stocks. Value stocks also may underperform the market for long periods of time.

Small and Mid-Cap Company Risk: Securities of small and mid-cap companies are often less liquid than those of large companies and this could make it difficult to sell a small or mid-cap company security at a desired time or price. As a result, small and mid-cap company stocks may fluctuate relatively more in price. In general, small and mid-capitalization companies are also more vulnerable than larger companies to adverse business or economic developments and they may have more limited resources.

6

Dimensional Fund Advisors

Emerging Markets Risk: Numerous emerging market countries have a history of, and continue to experience serious, and potentially continuing, economic and political problems. Stock markets in many emerging market countries are relatively small, expensive to trade in and generally have higher risks than those in developed markets. Securities in emerging markets also may be less liquid than those in developed markets and foreigners are often limited in their ability to invest in, and withdraw assets from, these markets. Additional restrictions may be imposed under other conditions. Frontier market countries generally have smaller economies or less developed capital markets and, as a result, the risks of investing in emerging market countries are magnified in frontier market countries.

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.

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 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.

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.

Call Risk: Call risk is the risk that during periods of falling interest rates, an issuer will call or repay a higher-yielding fixed income security before its maturity date, forcing a fund to reinvest in fixed income securities with lower interest rates than the original obligations.

Derivatives Risk: Derivatives are instruments, such as futures contracts, and options thereon, and foreign currency forward contracts, whose value is derived from that of

Dimensional VA Global Moderate Allocation Portfolio

7

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. 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 a fund between the date a foreign currency forward contract is entered into and the date it expires. 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.

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.

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.

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.

8

Dimensional Fund Advisors

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 table also includes the performance of additional indexes with similar investment universes of the Portfolio, or certain portions of the Portfolio. 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.

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 VA Global Moderate Allocation Portfolio

9

Dimensional VA Global Moderate Allocation Portfolio Institutional Class Shares -Total Returns

January 2014-December 2023

Highest Quarter

Lowest Quarter

14.04% 2020, Q2

-16.53% 2020, Q1

10

Dimensional Fund Advisors

Annualized Returns (%)
Periods ended December 31, 2023

1 Year

5 Years

10 Years

Dimensional VA Global Moderate Allocation Portfolio

Return Before Taxes

14.72%

8.93%

6.07%

Return After Taxes on Distributions

13.21%

7.74%

5.05%

Return After Taxes on Distributions and Sale of Portfolio Shares

8.89%

6.64%

4.42%

Dimensional VA Global Moderate Allocation Composite Index1

(reflects no deduction for fees, expenses or taxes)

15.57%

8.11%

5.66%

S&P Global BMI Index (net dividends)2

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

21.32%

11.23%

7.64%

ICE BofA 1-3 Year Global Government Index (hedged to USD)3

(reflects no deduction for fees, expenses or taxes)

4.84%

1.48%

1.33%

MSCI All Country World Index (net dividends)

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

22.20%

11.72%

7.93%

1.

Dimensional VA Global Moderate Allocation Composite Index is an unmanaged hypothetical index composed of 65% S&P Global BMI Index (net dividends) and 35% ICE BofA 1-3 Year Global Government Index (hedged to USD).

2.

Effective February 28, 2024, the Portfolio incorporated this broad-based securities market index to reflect the overall applicable securities market of the Portfolio.

3.

ICE BofA index data copyright 2023 ICE Data Indices, LLC. Prior to July 1, 2022, index returns reflect no deduction for transaction costs. Effective July 1, 2022, index returns include transaction costs (as determined and calculated by the index provider), which may be higher or lower than the actual transaction costs incurred by the Portfolio.

Investment Advisor/Portfolio Management

Dimensional Fund Advisors LP serves as the investment advisor for the Portfolio. The following individuals are responsible for leading the day-to-day management of the Portfolio:

• Jed S. Fogdall, Global Head of Portfolio Management, Chairman of the Investment Committee, Vice President, and Senior Portfolio Manager of the Advisor, has been a portfolio manager of the Portfolio since inception (2013).

• 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 (2013).

Dimensional VA Global Moderate Allocation Portfolio

11

• 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 (2013).

• Mary T. Phillips, Deputy Head of Portfolio Management, North America, member of the Investment Committee, Vice President, and Senior Portfolio Manager of the Advisor, has been a portfolio manager of the Portfolio since 2017.

• Allen Pu, Deputy Head of Portfolio Management, North America, member of the Investment Committee, Vice President, and Senior Portfolio Manager of the Advisor, has been a portfolio manager of the Portfolio since 2017.

• Ashish P. Bhagwanjee, Vice President and Senior Portfolio Manager of the Advisor, has been a portfolio manager of the Portfolio since 2020.

Purchase and Redemption of Fund Shares

Shares of the Portfolio are sold only to insurance company separate accounts or to other investment companies funded by insurance company separate accounts. 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 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

12

Dimensional Fund Advisors

financial advisor, visit your financial intermediary's website or see the prospectus of the insurance company separate account for more information.

Dimensional VA Global Moderate Allocation Portfolio

13

[THIS PAGE INTENTIONALLY LEFT BLANK]

[THIS PAGE INTENTIONALLY LEFT BLANK]

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

COMM-022824-004-7

00295879

Dimensional VA Global Moderate Allocation Portfolio
(formerly, VA Global Moderate Allocation Portfolio)

SHARE CLASS: CLASS L10

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 VA Global Moderate Allocation Portfolio (the "Portfolio") is to seek total return consisting of capital appreciation and current income.

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

0.23%

Other Expenses:

Shareholder Services Fees1

0.10%

Remainder of Other Expenses2

0.01%

Total Other Expenses

0.11%

Acquired Fund Fees & Expenses

0.20%

Total Annual Fund Operating Expenses

0.54%

Fee Waiver and/or Expense Reimbursement3

0.19%

Total Annual Fund Operating Expenses After Fee Waiver and/or Expense Reimbursement

0.35%

1

"Shareholders Services Fees" are paid to third parties that provide administrative and shareholder services to investors.

2

The Class L10 shares of the Portfolio are new, so the "Other Expenses" shown for the class are based on anticipated fees and expenses for the first full fiscal year.

3

Dimensional Fund Advisors LP (the "Advisor") has agreed to waive certain fees and in certain instances, assume certain expenses of the Portfolio. The Fee Waiver and/or Expense Assumption Agreement for the Portfolio will remain in effect through February 28, 2025, 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.

2

Dimensional Fund Advisors

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. The costs for the 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 whether you redeem or hold your shares would be:

1 Year

3 Years

$36

$154

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. The Portfolio does not pay transaction costs when buying and selling shares of other funds managed by the Advisor (the "Underlying Funds"); however, the Underlying Funds pay transaction costs when buying and selling securities for their portfolio. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Portfolio's performance. During the most recent fiscal year, the Portfolio's portfolio turnover rate was 24% based on the weighted average portfolio turnover ratios of each of the Portfolio's underlying investments.

Principal Investment Strategies

The VA Global Moderate Allocation Portfolio is a "fund of funds", which means that the Portfolio generally allocates its assets among other funds managed by the Advisor, although it has the ability to invest directly in securities and derivatives. To achieve the Portfolio's and the Underlying Funds' investment objectives, the Advisor implements an integrated investment approach that combines research, portfolio design, portfolio management, and trading functions. As further described below, the Portfolio's and the Underlying Funds' designs emphasize long-term drivers of expected returns identified by the Advisor's research, while balancing risk through broad diversification across companies and sectors. The Advisor's portfolio management and trading processes further balance those long-term drivers of expected returns with shorter-term drivers of expected returns and trading costs.

The VA Global Moderate Allocation Portfolio, under normal market circumstances, purchases shares of the Underlying Funds to achieve a moderate allocation to both global equity and global fixed income securities. Generally, the Portfolio invests its

Dimensional VA Global Moderate Allocation Portfolio

3

assets in domestic and international equity Underlying Funds and fixed income Underlying Funds to achieve an allocation that provides a moderate allocation to global equity securities, with an allocation of approximately 55% to 75% of the Portfolio's assets to domestic and international equity Underlying Funds and 25% to 45% of its assets to fixed income Underlying Funds. Periodically, the Advisor will review the allocations for the Portfolio in each Underlying Fund and may adjust allocations to Underlying Funds or may add or remove Underlying Funds in the Portfolio without notice to shareholders.

In addition to its allocation strategy of providing exposure to the domestic and international equity and fixed income markets through investment in the Underlying Funds, the VA Global Moderate Allocation Portfolio further diversifies its investment portfolio by allocating its assets among Underlying Funds that represent a variety of different asset classes. As of the date of this Prospectus, the Portfolio invests in: (1) domestic equity Underlying Funds that purchase a broad and diverse portfolio of securities of U.S. operating companies of all market capitalization sizes with an emphasis on smaller, lower relative price, and higher profitability companies and a domestic equity Underlying Fund that primarily invests in publicly traded real estate investment trusts ("REITs"); (2) international equity Underlying Funds that purchase a broad and diverse portfolio of securities of companies in developed ex U.S. and emerging markets of all market capitalization sizes which may include frontier markets (emerging market countries in an earlier stage of development) with an emphasis on smaller, lower relative price, and higher profitability companies and an international equity Underlying Fund that primarily invests in publicly traded REITs and REIT-like entities; 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, corporate debt obligations, bank obligations, commercial paper, repurchase agreements, money market funds, 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 Advisor may also increase or reduce the VA Global Moderate Allocation Portfolio's and/or Underlying Funds' exposure to an eligible company, or exclude a company, based on shorter-term considerations, such as a company's price momentum, short-run reversals, and investment characteristics. In assessing a company's investment characteristics, the Advisor considers ratios such as recent changes in assets divided by total assets. The criteria the Advisor uses for assessing a company's investment characteristics are subject to change from time to time. In addition, the Advisor seeks to reduce trading costs using a flexible trading approach that looks for opportunities to participate in the available market liquidity, while managing turnover and explicit transaction costs.

The VA Global Moderate Allocation Portfolio and each Underlying Fund may purchase or sell futures contracts and options on futures contracts, to increase or decrease market exposure based on actual or expected cash inflows to or outflows from the Portfolio or Underlying Fund. Certain Underlying Funds may enter into

4

Dimensional Fund Advisors

foreign currency exchange transactions, including foreign currency forward contracts, in connection with the settlement of foreign securities, 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.

Certain fixed income Underlying Funds also may purchase or sell futures contracts and options on futures contracts, to hedge their interest rate or currency exposure or for non-hedging purposes, such as a substitute for direct investment. Also the Portfolio and Underlying Funds may lend their portfolio securities to generate additional income.

Certain of the Underlying Funds are available for investment only by insurance company separate accounts that fund variable life and variable annuity contracts.

A summary of the investment strategies and policies of the Underlying Funds in which the VA Global Moderate Allocation Portfolio invests as of the date of this Prospectus is described in the Portfolio's Prospectus in the section entitled "ADDITIONAL INFORMATION ON INVESTMENT OBJECTIVES AND POLICIES-Investments in Underlying Funds."

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 a fund of funds is affected by the investment performance of the underlying funds in which the fund of funds invests. The ability of a fund of funds 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 a fund of funds' assets among the underlying funds. A fund of funds may allocate assets to an underlying fund or asset class that underperforms other funds or asset classes. There can be no assurance that the investment objective of a fund of funds or any underlying fund will be achieved. Through its investments in the underlying funds, a fund of funds is subject to the risks of the underlying funds' investments. When a fund of funds invests in underlying funds, investors are exposed to a proportionate share of the expenses of those underlying funds in addition to the expenses of a fund of funds. Certain risks of the Underlying Funds' investments that are principal risks of investing in the Portfolio are described below.

Equity Market Risk: Even a long-term investment approach cannot guarantee a profit. Economic, market, political, and issuer-specific conditions and events will cause the

Dimensional VA Global Moderate Allocation Portfolio

5

value of equity securities, and a fund that owns them, to rise or fall. Stock markets are volatile, with periods of rising prices and periods of falling prices.

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.

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).

Depositary receipts are generally subject to the same risks as the foreign securities that they evidence or into which they may be converted. In addition, the underlying issuers of certain depositary receipts, particularly unsponsored or unregistered depositary receipts, are under no obligation to distribute shareholder communications to the holders of such receipts, or to pass through to them any voting rights with respect to the deposited securities. Depositary receipts that are not sponsored by the issuer may be less liquid and there may be less readily available public information about the issuer.

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.

Profitability Investment Risk: High relative profitability stocks may perform differently from the market as a whole and an investment strategy purchasing these securities may cause a fund to at times underperform equity funds that use other investment strategies.

Value Investment Risk: Value stocks may perform differently from the market as a whole and an investment strategy purchasing these securities may cause a fund to at times underperform equity funds that use other investment strategies. Value stocks can react differently to political, economic, and industry developments than the market as a whole and other types of stocks. Value stocks also may underperform the market for long periods of time.

6

Dimensional Fund Advisors

Small and Mid-Cap Company Risk: Securities of small and mid-cap companies are often less liquid than those of large companies and this could make it difficult to sell a small or mid-cap company security at a desired time or price. As a result, small and mid-cap company stocks may fluctuate relatively more in price. In general, small and mid-capitalization companies are also more vulnerable than larger companies to adverse business or economic developments and they may have more limited resources.

Emerging Markets Risk: Numerous emerging market countries have a history of, and continue to experience serious, and potentially continuing, economic and political problems. Stock markets in many emerging market countries are relatively small, expensive to trade in and generally have higher risks than those in developed markets. Securities in emerging markets also may be less liquid than those in developed markets and foreigners are often limited in their ability to invest in, and withdraw assets from, these markets. Additional restrictions may be imposed under other conditions. Frontier market countries generally have smaller economies or less developed capital markets and, as a result, the risks of investing in emerging market countries are magnified in frontier market countries.

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.

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 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.

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.

Dimensional VA Global Moderate Allocation Portfolio

7

Call Risk: Call risk is the risk that during periods of falling interest rates, an issuer will call or repay a higher-yielding fixed income security before its maturity date, forcing a fund to reinvest in fixed income securities with lower interest rates than the original obligations.

Derivatives Risk: Derivatives are instruments, such as futures contracts, 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 a fund or if the cost of the derivative outweighs the benefit of the hedge. 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 a fund between the date a foreign currency forward contract is entered into and the date it expires. 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.

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.

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.

Operational Risk: Operational risks include human error, changes in personnel, system changes, faults in communication, and failures in systems, technology, or

8

Dimensional Fund Advisors

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 VA Global Moderate Allocation Portfolio's returns and are meant to provide some indication of the risks of investing in the Portfolio. The Class L10 shares of the Portfolio are a new class of shares for which performance information is not available, therefore, the bar chart and table show performance information for the Institutional Class shares of the Portfolio, another class of shares of the Portfolio not offered in this Prospectus. The bar chart shows the changes in performance of the Institutional Class shares of the Portfolio 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 of the Institutional Class shares of the Portfolio for certain periods compare with those of a broad measure of market performance. The table also includes the performance of additional indexes with similar investment universes of the Portfolio, or certain portions of the Portfolio. 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.

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 VA Global Moderate Allocation Portfolio

9

Dimensional VA Global Moderate Allocation Portfolio Institutional Class Shares1 -Total Returns

January 2014-December 2023

Highest Quarter

Lowest Quarter

14.04% 2020, Q2

-16.53% 2020, Q1

10

Dimensional Fund Advisors

Annualized Returns (%)
Periods ended December 31, 2023

1 Year

5 Years

10 Years

Dimensional VA Global Moderate Allocation Portfolio

Return Before Taxes

14.72%

8.93%

6.07%

Return After Taxes on Distributions

13.21%

7.74%

5.05%

Return After Taxes on Distributions and Sale of Portfolio Shares

8.89%

6.64%

4.42%

Dimensional VA Global Moderate Allocation Composite Index2

(reflects no deduction for fees, expenses or taxes)

15.57%

8.11%

5.66%

S&P Global BMI Index (net dividends)3

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

21.32%

11.23%

7.64%

ICE BofA 1-3 Year Global Government Index (hedged to USD)4

(reflects no deduction for fees, expenses or taxes)

4.84%

1.48%

1.33%

MSCI All Country World Index (net dividends)

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

22.20%

11.72%

7.93%

1.

The Institutional Class shares of the Portfolio would have substantially similar annual returns as the Class L10 shares because the shares are invested in the same portfolio securities. Returns for the Class L10 shares and Institutional Class shares will differ to the extent that the classes will have different expenses, and returns for the Class L10 shares would be expected to be lower than the returns of the Institutional Class shares to the extent that the Class L10 shares have higher expenses than the Institutional Class shares.

2.

Dimensional VA Global Moderate Allocation Composite Index is an unmanaged hypothetical index composed of 65% S&P Global BMI Index (net dividends) and 35% ICE BofA 1-3 Year Global Government Index (hedged to USD).

3.

Effective February 28, 2024, the Portfolio incorporated this broad-based securities market index to reflect the overall applicable securities market of the Portfolio.

4.

ICE BofA index data copyright 2023 ICE Data Indices, LLC. Prior to July 1, 2022, index returns reflect no deduction for transaction costs. Effective July 1, 2022, index returns include transaction costs (as determined and calculated by the index provider), which may be higher or lower than the actual transaction costs incurred by the Portfolio.

Investment Advisor/Portfolio Management

Dimensional Fund Advisors LP serves as the investment advisor for the Portfolio. The following individuals are responsible for leading the day-to-day management of the Portfolio:

Dimensional VA Global Moderate Allocation Portfolio

11

• Jed S. Fogdall, Global Head of Portfolio Management, Chairman of the Investment Committee, Vice President, and Senior Portfolio Manager of the Advisor, has been a portfolio manager of the Portfolio since inception (2013).

• 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 (2013).

• 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 (2013).

• Mary T. Phillips, Deputy Head of Portfolio Management, North America, member of the Investment Committee, Vice President, and Senior Portfolio Manager of the Advisor, has been a portfolio manager of the Portfolio since 2017.

• Allen Pu, Deputy Head of Portfolio Management, North America, member of the Investment Committee, Vice President, and Senior Portfolio Manager of the Advisor, has been a portfolio manager of the Portfolio since 2017.

• Ashish P. Bhagwanjee, Vice President and Senior Portfolio Manager of the Advisor, has been a portfolio manager of the Portfolio since 2020.

Purchase and Redemption of Fund Shares

Class L10 shares of the VA Global Moderate Allocation Portfolio are sold only to insurance company separate accounts used to fund variable life and variable annuity insurance contracts. Contract owners do not deal directly with the Fund with respect to the acquisition or redemption of shares of the Portfolio. Please see the offering material of the insurance company separate account for information regarding the purchase and redemption of Class L10 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

12

Dimensional Fund Advisors

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 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.

Dimensional VA Global Moderate Allocation Portfolio

13

[THIS PAGE INTENTIONALLY LEFT BLANK]

[THIS PAGE INTENTIONALLY LEFT BLANK]

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

Stradley Ronon Stevens & Young, LLP
2600 One Commerce Square
Philadelphia, PA 19103-7098
Telephone 215.564.8000
Fax 215.564.8120
www.stradley.com

1933 Act Rule 497(k)
1933 Act File No. 002-73948
1940 Act File No. 811-03258
November 15, 2024
VIA EDGAR

Filing Desk
U.S. Securities and Exchange Commission
100 F Street, N.E.
Washington, D.C. 20549
Re:
DFA Investment Dimensions Group Inc. (the "Registrant")
File Nos. 002-73948 and 811-03258
Rule 497(k) Filing

Ladies and Gentlemen:
Enclosed for filing under Rule 497(k) of the Securities Act of 1933, as amended, are summary prospectuses dated November 15, 2024, relating to the Dimensional VA Global Moderate Allocation Portfolio (formerly, VA Global Moderate Allocation Portfolio), a series of the Registrant.
Please direct questions or comments relating to this filing to me at (215) 564-8082 or, in my absence, to Jana Cresswell, Esq. at (215) 564-8048.

Very truly yours,
/s/ Brian Crowell
Brian Crowell, Esq.