ARTICLES SUPPLEMENTARY TO THE CHARTER

DFA INVESTMENT DIMENSIONS GROUP INC., a Maryland corporation having its principal office in Baltimore, Maryland (hereinafter called the “Corporation”) and registered under the Investment Company Act of 1940, as amended (the “1940 Act”), as an open-end management investment company, hereby certifies, in accordance with the requirements of Section 2-208 and/or 2-208.1 of the Maryland General Corporation Law (the “MGCL”), to the State Department of Assessments and Taxation of Maryland that:

FIRST:  The total number of shares of capital stock which the Corporation is authorized to issue is Two Hundred and Sixty Billion (260,000,000,000) shares of capital stock, with a par value of $0.01 per share, for an aggregate par value of Two Billion, Six Hundred Million Dollars ($2,600,000,000).  Currently, the Corporation’s authorized Shares have been designated and classified into the following 103 Series, and the Series have been subdivided into the following Classes:

In addition, 107,600,000,000 Shares remain unallocated and undesignated.

SECOND: The Board of Directors of the Corporation has adopted resolutions: (i) classifying and allocating Six Billion (6,000,000,000) shares of the unallocated and unissued shares of capital stock with a par value of One Cent ($0.01) per share, as follows: Five Hundred Million (500,000,000) shares of capital stock were allocated to the class of shares designated “ETF Class” of the Series designated as “U.S. Large Cap Equity Portfolio”; Five Hundred Million (500,000,000) shares of capital stock were allocated to the class of shares designated “ETF Class” of the Series designated as “U.S. Small Cap Value Portfolio”; Five Hundred Million (500,000,000) shares of capital stock were allocated to the class of shares designated “ETF Class” of the Series designated as “U.S. Targeted Value Portfolio”; Five Hundred Million (500,000,000) shares of capital stock were allocated to the class of shares designated “ETF Class” of the Series designated as “U.S. Core Equity 1 Portfolio”; Five Hundred Million (500,000,000) shares of capital stock were allocated to the class of shares designated “ETF Class” of the Series designated as “U.S. Core Equity 2 Portfolio”; Five Hundred Million (500,000,000) shares of capital stock were allocated to the class of shares designated “ETF Class” of the Series designated as “U.S. Vector Equity Portfolio”; Five Hundred Million (500,000,000) shares of capital stock were allocated to the class of shares designated “ETF Class” of the Series designated as “U.S. Small Cap Portfolio”; Five Hundred Million (500,000,000) shares of capital stock were allocated to the class of shares designated “ETF Class” of the Series designated as “U.S. Micro Cap Portfolio”; Five Hundred Million (500,000,000) shares of capital stock were allocated to the class of shares designated “ETF Class” of the Series designated as “U.S. High Relative Profitability Portfolio”;  Five Hundred Million (500,000,000) shares of capital stock were allocated to the class of shares designated “ETF Class” of the Series designated as “DFA Real Estate Securities Portfolio”; Five Hundred Million (500,000,000) shares of capital stock were allocated to the class of shares designated “ETF Class” of the Series designated as “U.S. Large Cap Growth Portfolio”; and Five Hundred Million (500,000,000) shares of capital stock were allocated to the class of shares designated “ETF Class” of the Series designated as “U.S. Small Cap Growth Portfolio”:

THIRD: Following the aforesaid classifications, allocations, and designations, the Corporation has the authority to issue Two Hundred and Sixty Billion (260,000,000,000) shares of capital stock, with a par value of $0.01 per share, having an aggregate par value of Two Billion, Six Hundred Million Dollars ($2,600,000,000), which shares of capital stock have been designated and classified into the following 103 Series, and such Series have been subdivided into the following  Classes:

In addition, 101,600,000,000 Shares remain unallocated and undesignated.

FOURTH:  The shares of capital stock designated, allocated and classified pursuant to these Articles Supplementary shall have such preferences, conversion and other rights, voting powers, restrictions, limitations as to dividends, qualifications and terms and conditions of redemption as are set forth in the Charter of the Corporation.

FIFTH:  The shares aforesaid have been duly classified by the Board of Directors pursuant to authority contained in the Charter of the Corporation and, to the extent applicable, in accordance with Sections 2-105(c), 2-208 and/or 2-208.1 of the MGCL.

SIXTH:  These Articles Supplementary shall become effective upon filing.

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IN WITNESS WHEREOF, DFA Investment Dimensions Group Inc. has caused these Articles Supplementary to be signed and acknowledged in its name and on its behalf by its Vice President and attested to by its Assistant Secretary on this 6^th day of January, 2026; and its Vice President acknowledges that these Articles Supplementary are the act of DFA Investment Dimensions Group Inc., and she further acknowledges that, as to all matters or facts set forth herein which are required to be verified under oath, such matters and facts are true in all material respects to the best of her knowledge, information and belief, and that this statement is made under the penalties for perjury.