- Mainstreet
- Mainstreet Investments
- Maison DeVille Nursing Home
- Maison DeVille Nursing Home of Harvey
- Maison Orleans Healthcare Center
- Majestic Care
- Managed Care & Contract Consulting
- Managed Medicare
- Management and Network Services
- Manatt Health
- Manchester Manor Health Care Center
- ManorCare
- Marcum LLP
- Marcus & Milichap
- Marcus & Millichap
- Margaritaville Holdings
- Margolis Center for Health Policy
- Mariner Health Care Inc.
- Maritime Center for Rehabilitation and Nursing
- MarketWatch