- Mercy Health System
- Mercy Home Health
- Mercy LIFE
- Mercyhealth
- Merfi
- Merfi Corporation
- Meridian Institute
- Meridius Health
- Merrill Lynch
- Merrimack Valley Hospice
- Mertz Taggart
- Methodist Health System
- Methodist Senior Home Care
- MetLife
- MetLife Mature Market Institute
- Metro Dade Home Health INc
- Metrostudy
- MHHA
- Mical Home Health Care
- Michigan Health Endowment