- Mississippi Methodist Rehabilitation Center
- Mississippi State Hospital
- Mississippi State Penitentiary Hospital
- Missouri Baptist Medical Center
- Missouri Baptist Sullivan Hospital
- Missouri Delta Medical Center
- Missouri Orthopaedic Institute
- Missouri Psychiatric Center
- Mitchell County Hospital
- Mitchell County Hospital Health Systems
- Mitchell County Regional Health Center
- Mizell Memorial Hospital
- MLK Community Hospital
- Moab Regional Hospital
- Moberly Regional Medical Center
- Mobile Infirmary
- Mobridge Regional Hospital
- Moccasin Bend Mental Health Institute
- Modesto Medical Center
- Modoc Medical Center
- Moffitt Cancer Center Magnolia Campus
- Moffitt Cancer Center McKinley Hospital
- Mohawk Valley Psychiatric Center
- Molokai General Hospital
- Monadnock Community Hospital
- Mon Health Marion Neighborhood Hospital
- Mon Health Medical Center
- Monmouth Medical Center
- Monmouth Medical Center Southern Campus
- Monroe Carell Jr Childrens Hospital at Vanderbilt