- Marsh McLennan
- Marx Development Group
- Maryhurst
- Maryland
- Maryland Baptist Aged Home
- maryland department of health
- Maryland Health Care Commission
- Masonic Homes Covina Citrus Heights Health Center
- Masonic Homes of California
- Masonicare
- Mass General Brigham
- Massachusetts Department of Health
- Massachusetts Executive Office of Health and Human Services
- Massachusetts Health & Hospital Association
- Massachusetts Office of Attorney General
- Massachusetts Senior Action Council
- Massachusetts Senior Care Association
- Massachusetts Senior Coalition
- Mathematica Center
- Mather LifeWays