- Shriners Hospitals for Children
- Signature Healthcare
- Signature Healthcare Services
- Silver Cross Hospital
- Sinai Health System
- Singing River Health System
- Sistema de Salud Episcopal San Lucas
- Sisters of Mary of Presentation Health System
- Skagit Regional Health
- Sky Lakes Medical Center
- SolutionHealth
- South Carolina Department of Mental Health
- Southcoast Health System
- South County Health
- South Davis Community Hospital
- Southeast Alaska Regional Health Consortium
- Southeast Georgia Health System
- Southeast Health
- Southern California Hospital
- Southern Crescent Behavioral Health System
- Southern Illinois Healthcare
- Southern Illinois Health Care Foundation
- Southern New Hampshire Health
- Southern Tennessee Regional Health System
- South Georgia Medical Center
- South Shore Health System
- South Texas Health System
- Southwest Healthcare System
- Southwest Health System
- Sovah Health