Select Medical Holdings Corporation operates various healthcare facilities, including critical illness recovery hospitals, rehabilitation hospitals, outpatient rehabilitation clinics, and occupational health centers in the United States, providing therapy and rehabilitation treatments for various medical conditions. Their services cater to heart failure, respiratory failure, renal disease, and neurological events, among others. As of December 2021, the company had a broad presence, operating in 41 states, with 104 critical illness recovery hospitals, 30 rehabilitation hospitals, 1,881 outpatient rehabilitation clinics, and 518 occupational health centers.