X0609 4 2026-06-30 1 0001320414 SELECT MEDICAL HOLDINGS CORP SEM 0001168882 JACKSON MARTIN F false C/O SELECT MEDICAL HOLDINGS CORPORATION 4714 GETTYSBURG ROAD MECHANICSBURG PA 17055 false true false false EXECUTIVE VICE PRESIDENT 0 Common Stock 2026-06-30 4 J 0 1383421 0 D 0 D Common Stock 2026-06-30 4 J 0 2634 0 D 0 I By son Common Stock 2026-06-30 4 J 0 2634 0 D 0 I By daughter Common Stock 2026-06-30 4 J 0 2634 0 D 0 I By son Common Stock 2026-06-30 4 J 0 2634 0 D 0 I By son This Form 4 reports securities disposed of under the Agreement and Plan of Merger (the "Merger Agreement"), entered into on March 2, 2026, by and among the Issuer, Stallion Intermediate Corporation ("Parent"), and Stallion MergerSub Corporation (filed as Exhibit 2.1 to the Form 8-K filed with the Securities and Exchange Commission on March 3, 2026). Immediately prior to the effective time of the merger, the reporting person contributed 1,138,754 common shares and 244,667 restricted shares to Parent in exchange for an equivalent amount of shares of common stock ("Parent Common Shares") and restricted shares, respectively, of Parent, which Parent Common Shares were then exchanged for an equivalent amount of interests in Stallion Group Parent, LP. Immediately prior to the effective time of the merger, the Reporting Person contributed 2,634 common shares to Parent in exchange for an equivalent amount of shares of Parent Common Shares, which Parent Common Shares were then exchanged for an equivalent amount of interests in Stallion Group Parent, LP. The reporting person beneficially owns the reported securities indirectly, but disclaims beneficial ownership of the reported securities except to the extent of his pecuniary interest therein. /s/ John F. Duggan, Attorney-in-Fact 2026-07-01