Select Medical Holdings Corp. engages in the provision of medical rehabilitation services. The company is headquartered in Mechanicsburg, Pennsylvania and currently employs 30,000 full-time employees. The company went IPO on 2009-09-25. 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. The company 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. The company 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.