- Metro Health Foundation, Inc.
- Metro Public Health Department
- Metro South West Health Corp.
- Metro United Way
- MetroHealth
- Metroplan Orlando
- Metropolitan Chicago Healthcare Council
- Metropolitan Community Health Service
- Metropolitan Family Services
- Metropolitan Methodist Hospital
- Metropolitan Transit Authority METRO)
- Metropolitan Tucson Convention and Visitors Bureau
- MetroSouth Medical Center
- MetroWest Medical Center - Framingham and Natick
- MetroWest Medical Center - Leonard Morse Hospital
- Meydenbauer Center
- MGM Grand
- MHF Logistical Solutions Inc.
- MHP Communications LLC
- Miami Transplant Institute
- Miami Valley Career Technical Center
- Miami Valley Hospital
- Miami-Dade Community College
- Michael Baker Jr. Inc.
- Michael E. DeBakey Veterans Affairs Medical Center
- Michael Foods Inc.
- Michael Thomas Furniture Incorporated
- Michael-Gene Kids Basketball Foundation
- Michigan Dental Association
- Michigan Department of Community Health
- Michigan Department of State
- Michigan Health and Hospital Association
- Michigan Medicine
- Michigan Primary Care Association
- Michigan Society of Association Executives
- Michigan State University
- Michigan Townships Association
- MicroAge
- Microchip Technology
- MICROMAIN Corporation
- Microsoft
- Microsoft Corporation
- Microtel Inn and Suites by Wyndham Anchorage Airport
- Microtel Inn Atlanta Airport
- Microtel Inn Atlanta-Smyrna
- Microtel Inn, Newport News
- Mid Atlantic Events Magazine
- Mid Coast Hospital
- Mid Coast Medical Group-Family Practice at Parkview
- Mid Coast-Parkview Health