- Cincinnati Childrens Hospital Medical Center
- Circle Health
- Citizens Memorial Healthcare
- City of Hope
- ClearSky Health
- Cleveland Clinic Akron General
- Cleveland Clinic Florida
- Coastal Carolinas Health Alliance
- Coastal Harbor Health System
- Cohesive Healthcare Management & Consulting
- College Health Enterprises
- Colquitt Regional Medical Center
- Columbus Regional Health
- Comanche County Memorial Hospital
- CommonSpirit
- Commonwealth Health
- Commonwealth Health Corporation
- CommuniCare Health Services
- Community Foundation of Northwest Indiana
- Community HealthCare System
- Community Health Network
- Community Health Systems
- Community Hospital Corporation
- Community Hospital Corporation ContinueCARE
- Community Howard Regional Health
- Community Medical Centers
- Community Memorial Health System
- Community Memorial Hospital Association
- Compass Health
- Concord Hospital Health System