Material Event (Form 8-K)

Item 8.01 - Other Events.

On May 19, 2026, Select Medical Holdings Corporation (the "Company" or "Select Medical") filed with the U.S. Securities and Exchange Commission (the "SEC") a definitive proxy statement (the "Definitive Proxy Statement") with respect to the special meeting of the Company's stockholders scheduled to be held on June 26, 2026 to, among other things, vote on a proposal to approve the previously announced acquisition of the Company by an entity affiliated with a consortium led by Robert A. Ortenzio, Executive Chairman, Co-Founder and Director of Select Medical, Martin F. Jackson, Senior Executive Vice President of Strategic Finance and Operations of Select Medical, and Welsh, Carson, Anderson & Stowe, pursuant to the Agreement and Plan of Merger (the "Merger Agreement"), dated as of March 2, 2026, by and among the Company, Stallion Intermediate Corporation, a Delaware corporation ("Parent"), and Stallion MergerSub Corporation, a Delaware corporation and a direct wholly owned Subsidiary of Parent ("Merger Sub"), pursuant to which Merger Sub will merge with and into the Company, with the Company continuing as the surviving corporation and a wholly-owned subsidiary of Parent (the "Merger").

As of the date of this Current Report on Form 8-K, two complaints have been filed in the Supreme Court of the State of New York, County of New York (the "New York Complaints") and one complaint has been filed in the Court of Common Pleas of Cumberland County, Pennsylvania, Ninth Judicial District (the "Pennsylvania Complaint," and together with the New York Complaints, the "Complaints"). The New York Complaints are captioned as follows: Mark Stevens v. Select Medical Holdings Corporation, Robert A. Ortenzio, David S. Chernow, Russell L. Carson, Katherine R. Davisson, William H. Frist, Marilyn B. Tavenner, Daniel J. Thomas, Parvinderjit S. Khanuja, James S. Ely III, and Thomas A. Scully, Index No. 653282/2026; and Robert Jones v. Select Medical Holdings Corporation, Robert A. Ortenzio, David S. Chernow, Russell L. Carson, Katherine R. Davisson, William H. Frist, Marilyn B. Tavenner, Daniel J. Thomas, Parvinderjit S. Khanuja, James S. Ely III, and Thomas A. Scully, Index No. 653290/2026. The Pennsylvania Complaint is captioned as follows: Dean Drulias v. Russell Carson; David Chernow; Katherine Davisson; James Ely III; William Frist; Parvinderjit Khanuja; Robert Ortenzio; Thomas Scully; Marilyn Tavenner; Daniel Thomas; Select Medical Holdings Corporation; Welsh, Carson, Anderson & Stowe; WCAS XIV, L.P.; WCAS XIV Associates LLC; WCAS Management, L.P.; and WCAS Management, LLC, Case No. 2026-06775-0. The Complaints generally allege that the Definitive Proxy Statement misrepresents and/or omits certain purportedly material information regarding the Merger. The Complaints assert claims under New York and Pennsylvania common law for negligent misrepresentation and concealment, and negligence against the Company and the members of the Company's board of directors. The Pennsylvania Complaint additionally asserts claims under Pennsylvania common law for fraudulent concealment and non-disclosure against all defendants and violations of the Pennsylvania Securities Act of 1972 against Welsh, Carson, Anderson & Stowe; WCAS XIV, L.P.; WCAS XIV Associates LLC; WCAS Management, L.P.; and WCAS Management, LLC. The Complaints seek, among other things, to enjoin the consummation of the Merger and attorneys' fees. The New York Complaints also seek actual and punitive damages if the Merger is consummated.

In addition, the Company has received demand letters from eleven purported stockholders of the Company (together with the Complaints, the "Matters") alleging similar deficiencies regarding the disclosures made in the Definitive Proxy Statement regarding the Merger, and seeking additional disclosures in the Definitive Proxy Statement to address those purported deficiencies.

While the Company believes that the disclosures set forth in the Definitive Proxy Statement comply fully with all applicable law and denies the allegations in the Matters described above, in order to moot the purported stockholders' disclosure claims, avoid nuisance and possible expense and business delays, and provide additional information to its stockholders, the Company has determined voluntarily to supplement certain disclosures in the Definitive Proxy Statement related to the purported stockholders' claims with the supplemental disclosures set forth below (the "Supplemental Disclosures"). These Supplemental Disclosures should be read in conjunction with the rest of the Definitive Proxy Statement, which is available at the SEC's website, www.sec.gov, and which the Company urges you to read in its entirety. Nothing in the Supplemental Disclosures shall be deemed an admission of the legal merit, necessity or materiality under applicable laws of any of the disclosures set forth herein. To the contrary, the Company and the other named defendants specifically deny all allegations in the complaints, including the allegations that any additional disclosure was or is required or material.

To the extent that the information set forth herein differs from or updates information contained in the Definitive Proxy Statement, the information set forth herein shall supersede or supplement the information in the Definitive Proxy Statement. All references to sections and subsections herein are references to the corresponding sections or subsections in the Definitive Proxy Statement, all page references are to pages in the Definitive Proxy Statement, and terms used herein, unless otherwise defined, have the meanings set forth in the Definitive Proxy Statement. Unless stated otherwise, the new text in the Supplemental Disclosures is in boldface and underlined to highlight the supplemental information being disclosed, while deleted text is bold and stricken-through.