Exhibit 99.1

Select Medical Corporation’s Proposed Acquisition of

Concentra Inc. through Joint Venture with Welsh Carson Receives Antitrust Clearance

MECHANICSBURG, PENNSYLVANIA — May 20, 2015 — Select Medical Corporation (“Select”) today announced that the Federal Trade Commission granted early termination of the waiting period under the Hart-Scott-Rodino (HSR) Antitrust Improvements Act of 1976, as amended, applicable to the acquisition of Concentra Inc. (“Concentra”) by MJ Acquisition Corporation, a joint venture that Select has created with Welsh, Carson, Anderson & Stowe XII, L.P.

As previously announced, MJ Acquisition Corporation has signed a definitive purchase agreement to acquire all of the issued and outstanding equity securities of Concentra.  The early termination of the HSR waiting period satisfies one of the conditions to the closing of the acquisition.  The transaction, which is expected to close in the second quarter, remains subject to the other closing conditions set forth in the purchase agreement.

Select is a leading operator of specialty hospitals and outpatient rehabilitation clinics in the United States.  As of March 31, 2015, Select operated 112 long term acute care hospitals and 17 acute medical rehabilitation hospitals in 28 states and 1,028 outpatient rehabilitation clinics in 31 states and the District of Columbia.  Select also provides medical rehabilitation services on a contracted basis to nursing homes, hospitals, assisted living and senior care centers, schools and work sites.  Information about Select is available at www.selectmedical.com.

Certain statements contained herein that are not descriptions of historical facts are “forward-looking” statements (as such term is defined in the Private Securities Litigation Reform Act of 1995).  These statements are based on current information and belief, and are not guarantees of future performance. Among the risks and uncertainties that could cause actual results to differ materially from those indicated by such forward-looking statements include factors discussed from time to time in our filings with the Securities and Exchange Commission, including factors discussed under the heading “Risk Factors” of the annual report on Form 10-K and subsequent Forms 10-Q. Except as required by applicable law, including the securities laws of the United States and the rules and regulations of the SEC, we are under no obligation to publicly update or revise any forward-looking statements, whether as a result of any new information, future events or otherwise. You should not place undue reliance on our forward-looking statements. Although we believe that the expectations reflected in forward-looking statements are reasonable, we cannot guarantee future results or performance.

Investor inquiries:

Joel T. Veit

Senior Vice President and Treasurer

717-972-1100

ir@selectmedicalcorp.com

SOURCE: Select Medical Holdings Corporation