- Abrazo Health
- Acadia Healthcare
- AcuteCare Health System
- Adena Health System
- Adirondack Health
- Advanced Diagnostics Healthcare System
- AdventHealth
- Adventist Health
- Adventist Healthcare
- Adventist Health Hanford
- Advocate Health Care
- AHMC Healthcare
- Alabama Department of Mental Health
- Alameda Health System
- Alaska Area Native Health Service
- Albany Medical Center
- Alecto Healthcare Services
- Alita Care
- Allegheny Health Network
- Allegiance Health Management
- AllianceHealth Oklahoma
- Alliant Management Services
- Allied Services Integrated Health System
- Allina Health System
- Alta Los Angeles Hospitals
- AltaPointe Health Systems
- Altru Health System
- Altus Health System
- AmberMed
- Amberwell Health