- Mentor Hospital
- Mercer County Community Hospital
- Mercy Health - Allen Hospital
- Mercy Health - Anderson Hospital
- Mercy Health - Clermont Hospital
- Mercy Health - Defiance Hospital
- Mercy Health - Fairfield Hospital
- Mercy Health - Kings Mills Hospital
- Mercy Health - Lorain Hospital
- Mercy Health - Perrysburg Hospital
- Mercy Health Rehabilitation Hospital
- Mercy Health - Springfield Regional Medical Center
- Mercy Health - St Anne Hospital
- Mercy Health - St Charles Hospital
- Mercy Health - St Elizabeth Boardman Hospital
- Mercy Health - St Elizabeth Youngstown Hospital
- Mercy Health - St Joseph Warren Hospital
- Mercy Health - St Ritas Medical Center
- Mercy Health - St Vincent Medical Center
- Mercy Health - Tiffin Hospital
- Mercy Health - Urbana Hospital
- Mercy Health - West Hospital
- Mercy Health - Willard Hospital
- MetroHealth Cleveland Heights Medical Center
- MetroHealth Medical Center
- MetroHealth Parma Medical Center
- Miami Valley Hospital
- Miami Valley Hospital North
- Miami Valley Hospital South
- Morrow County Hospital