X0202 SCHEDULE 13G/A 0001104659-26-062726 0001721695 XXXXXXXX LIVE 1 Common Stock, par value $0.001 per share (the "Shares") 06/30/2026 0000910329 MEDIFAST INC 58470H101 1501 S. Clinton Street Suite 500 Baltimore MD 21224 Rule 13d-1(b) Citadel Securities GP LLC DE 0.00 236447.00 0.00 236447.00 236447.00 N 2.1 HC OO The percentages reported in this Schedule 13G are based upon 11,119,115 Shares outstanding as of April 27, 2026 (according to the issuer's Form 10-Q as filed with the Securities and Exchange Commission on May 4, 2026). Citadel Securities LLC DE 0.00 233401.00 0.00 233401.00 233401.00 N 2.1 BD OO Citadel Securities Group LP DE 0.00 236447.00 0.00 236447.00 236447.00 N 2.1 HC PN Citadel Advisors LLC DE 0.00 53304.00 0.00 53304.00 53304.00 N 0.5 IA HC OO Citadel Advisors Holdings LP DE 0.00 53304.00 0.00 53304.00 53304.00 N 0.5 HC PN Citadel GP LLC DE 0.00 53304.00 0.00 53304.00 53304.00 N 0.5 HC OO Kenneth Griffin X1 0.00 289751.00 0.00 289751.00 289751.00 N 2.6 HC IN MEDIFAST INC 1501 S. Clinton Street, Suite 500, Baltimore, MD 21224 This Schedule 13G is being jointly filed by Citadel Securities GP LLC ("CSGP"), Citadel Securities LLC ("Citadel Securities"), Citadel Securities Group LP ("CALC4"), Citadel Advisors LLC ("Citadel Advisors"), Citadel Advisors Holdings LP ("CAH"), Citadel GP LLC ("CGP"), and Mr. Kenneth Griffin (collectively with CSGP, Citadel Securities, CALC4, Citadel Advisors, CAH, and CGP, the "Reporting Persons") with respect to the Shares of the above-named issuer held of record by Citadel Quantitative Strategies Master Fund Ltd., a Cayman Islands limited company ("CQ"), Citadel Securities and Citadel Securities Principal Strategies LLC, a Delaware limited liability company ("CSP"). Such Shares may include other instruments exercisable for or convertible into Shares. CALC4 is the non-member manager of Citadel Securities and CSP. CSGP is the general partner of CALC4. Citadel Advisors is the portfolio manager for CQ. CAH is the sole member of Citadel Advisors. CGP is the general partner of CAH. Mr. Griffin is the President and Chief Executive Officer of CGP, and owns a controlling interest in CGP and CSGP. The address of each of the Reporting Persons is 830 Brickell Plaza, Miami, Florida 33131. Each of CSGP, Citadel Securities, Citadel Advisors, and CGP is organized as a limited liability company under the laws of the State of Delaware. Each of CALC4 and CAH is organized as a limited partnership under the laws of the State of Delaware. Mr. Griffin is a U.S. citizen. N BD IA HC 1. Citadel Securities LLC may be deemed to beneficially own 233,401 Shares. 2. Each of Citadel Securities Group LP and Citadel Securities GP LLC may be deemed to beneficially own 236,447 Shares. 3. Each of Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC may be deemed to beneficially own 53,304 Shares. 4. Mr. Griffin may be deemed to beneficially own 289,751 Shares. 1. The number of Shares that Citadel Securities LLC may be deemed to beneficially own constitutes 2.1% of the Shares outstanding. 2. The number of Shares that each of Citadel Securities Group LP and Citadel Securities GP LLC may be deemed to beneficially own constitutes 2.1% of the Shares outstanding. 3. The number of Shares that each of Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC may be deemed to beneficially own constitutes 0.5% of the Shares outstanding. 4. The number of Shares that Mr. Griffin may be deemed to beneficially own constitutes 2.6% of the Shares outstanding. 1. Citadel Securities LLC: 0 2. Each of Citadel Securities Group LP and Citadel Securities GP LLC: 0 3. Each of Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC: 0 4. Mr. Griffin: 0 1. Citadel Securities LLC: 233,401 2. Each of Citadel Securities Group LP and Citadel Securities GP LLC: 236,447 3. Each of Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC: 53,304 4. Mr. Griffin: 289,751 1. Citadel Securities LLC: 0 2. Each of Citadel Securities Group LP and Citadel Securities GP LLC: 0 3. Each of Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC: 0 4. Mr. Griffin: 0 1. Citadel Securities LLC: 233,401 2. Each of Citadel Securities Group LP and Citadel Securities GP LLC: 236,447 3. Each of Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC: 53,304 4. Mr. Griffin: 289,751 N Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11. Citadel Securities GP LLC /s/ Seth Levy 08/14/2026 Citadel Securities LLC /s/ Seth Levy 08/14/2026 Citadel Securities Group LP /s/ Seth Levy 08/14/2026 Citadel Advisors LLC /s/ Seth Levy 08/14/2026 Citadel Advisors Holdings LP /s/ Seth Levy 08/14/2026 Citadel GP LLC /s/ Seth Levy 08/14/2026 Kenneth Griffin /s/ Seth Levy 08/14/2026 * Seth Levy is signing on behalf of Kenneth Griffin as attorney-in-fact pursuant to a power of attorney previously filed with the Securities and Exchange Commission, and hereby incorporated by reference herein. The power of attorney was filed as an attachment to a filing by Citadel Advisors LLC on Schedule 13G for Allakos Inc. on October 13, 2023.