- Mountain Vista Medical Center
- Mountainlands Community Health Center
- Mountains Community Hospital
- Mountainside Residential Care Center
- MountainView Hospital
- MountainView Regional Medical Center
- MoveN Software, Inc.
- Mower
- MPI-The Meeting Professional Magazine
- MPW
- MRC Bearings, Inc
- MRI Technologies
- MS Baptist Medical Center
- MSJ OccuMed
- Mt. Ascutney Hospital
- MTC Technologies
- MTF Biologics - Jessup
- MTF Biologics - Main Office
- MU Sinclair School of Nursing
- Muhlenberg Regional Medical Center
- Muhlenkamp and Company Inc.
- Multi-Media Holdings, Inc.
- Multigen. Paradigm
- MultiNational Insurance Company
- Multistate Associates Incorporated
- Municipal Travel
- Municipio de Barceloneta
- Municipio De Camuy
- Municipio de Ponce
- Municipio de San German
- Municipio de Villalba
- Muniz Engineering Inc.
- Munson Healthcare
- Muray Boys and Girls Club
- Murphy Oil Corporation
- Murray Chamber of Commerce
- Murray City Police Department
- MUSC Health
- MUSC Health Lancaster Medical Center
- Muscogee County Humane Society
- Muscogee County Sheriff
- Muscogee Creek Nation
- Muscogee Manor and Rehabilitation Center.
- Muscular Dystrophy Association
- Muse
- Museum Store Association
- Muskegon Community Health Project
- Muskegon County
- Muskegon County, Michigan
- Muskegon Family Care