- Memorial Sloan Kettering Westchester
- Memphis Mental Health Institute
- Mena Regional Health System
- Mendota Mental Health Institute
- Menifee Global Medical Center
- Mennonite Hospital Cima
- Mennonite Hospital Guyama
- Mennonite Hospital Humacao
- Mennonite Hospital of Aibonito
- Mennonite Hospital of Caguas
- Mennonite Hospital Ponce
- Menorah Medical Center
- Mental Health Emergency Center Inc
- Mental Health Services for Clark County
- Mental Wellness Campus for youth and adults
- Mentor Hospital
- Mercer County Community Hospital
- Mercy Behavioral Hospital
- Mercy Catholic Medical Center - Mercy Fitzgerald Campus
- Mercy Childrens Hospital Springfield
- Mercy Childrens Hospital St Louis
- Mercy General Hospital
- Mercy Gilbert Medical Center
- Mercy Health - Allen Hospital
- Mercy Health - Anderson Hospital
- Mercy Health - Clermont Hospital
- Mercy Health - Defiance Hospital
- Mercy Health - Fairfield Hospital
- Mercyhealth Hospital and Medical Center - Harvard
- Mercyhealth Hospital and Medical Center - Walworth