Power of Attorney for William C. Cobb

This filing is an exhibit detailing a Power of Attorney granted by William C. Cobb, an officer and/or director of CarMax Inc. (KMX), to John M. Stuckey III, Terence Rasmussen, Christine Carter, and Chelsea Shrader. This power of attorney authorizes the appointed individuals to execute and file Forms 3, 4, and 5, or any amendments, on behalf of Mr. Cobb, in accordance with Section 16(a) of the Securities Exchange Act of 1934. The attorneys-in-fact are empowered to take any necessary actions to complete and file these forms, ensuring compliance with regulatory requirements. The power of attorney remains in effect until Mr. Cobb is no longer obligated to file these forms with respect to CarMax Inc. The filing also notes that the attorneys-in-fact and the Company are not assuming Mr. Cobb's responsibilities for Section 16 compliance. The document was executed on April 1, 2026, with a signature date of June 24, 2026.