Select Medical Holdings Corporation operates critical illness recovery hospitals, rehabilitation hospitals, and outpatient rehabilitation clinics in the United States. Its segments include Critical Illness Recovery Hospital, Rehabilitation Hospital, and Outpatient Rehabilitation. Critical Illness Recovery Hospital segment consists of hospitals designed to serve the needs of patients recovering from critical illnesses, often with complex medical needs. It operates the majority of its critical illness recovery hospitals as a hospital within a hospital (an HIH). Rehabilitation Hospital segment serves patients that require intensive physical rehabilitation care. Outpatient Rehabilitation segment consists of clinics that provide physical, occupational, and speech rehabilitation services. It operates around 105 critical illness recovery hospitals in 29 states, 36 rehabilitation hospitals in 14 states, and 1,922 outpatient rehabilitation clinics in 39 states and the District of Columbia.