Select Medical Holdings Corporation, through its subsidiaries, operates critical illness recovery hospitals, rehabilitation hospitals, and outpatient rehabilitation clinics in the United States. It operates through three segments: Critical Illness Recovery Hospital, Rehabilitation Hospital, and Outpatient Rehabilitation. The Critical Illness Recovery Hospital segment consists of hospitals that provide services for heart failure, infectious disease, respiratory failure and pulmonary disease, surgery requiring prolonged recovery, renal disease, neurological events, and trauma. Its Rehabilitation Hospital segment offers therapy and rehabilitation treatments, including rehabilitative services for brain and spinal cord injuries, strokes, amputations, neurological disorders, orthopedic conditions, pediatric congenital or acquired disabilities, and cancer.