- Aspirus Rhinelander Hospital
- Aspirus Riverview Hospital
- Aspirus Stanley Hospital
- Aspirus Stevens Point Hospital
- Aspirus Tomahawk Hospital
- Aspirus Wausau Hospital
- Assumption Community Hospital
- Assurance Health Anderson
- Assurance Health Cincinnati
- Assurance Health Hudson
- Assurance Health Indianapolis
- Assurance Health Toledo
- Astera Health
- Astria Sunnyside Hospital
- Astria Toppenish Hospital
- Athens-Limestone Hospital
- Athol Hospital
- AtlantiCare Regional Medical Center - Atlantic City Campus
- AtlantiCare Regional Medical Center - Mainland Campus
- Atlantic General Hospital
- Atlantic Rehabilitation Institute
- Atmore Community Hospital
- Atoka County Medical Center
- Atrium Health Anson
- Atrium Health Behavioral Health - Charlotte
- Atrium Health Behavioral Health - Davidson
- Atrium Health Cabarrus
- Atrium Health Carolinas Medical Center
- Atrium Health Cleveland
- Atrium Health Floyd Cherokee Medical Center