- Maine Innkeepers Association
- Maine Medical Center
- Maine Medical Center - Stevens Avenue
- Maine Office of Substance Abuse and Mental Health Services
- Maine Parent Federation
- MaineGeneral Medical Center
- MaineGeneral Rehabilitation and Long Term Care at Glenridge
- Maita Toyota of Sacramento
- Major County
- Major Hospital
- Major League Baseball Players Alumni
- Malco Theatres
- Malnove Holding Company, Inc.
- Malone College
- Management Advisors, Inc.
- Management Information Systems
- Management Information Systems
- Management Options Inc.
- Management Reemiters of Columbus
- Management Science Associates, Inc.
- Management Solutions Plus, Inc.
- Management Support Technology Inc.
- Manatee Chamber of Commerce
- Manatee County Clerk of Circuit Court
- Manatee County Family YMCA, Inc.
- Manatee Memorial Hospital
- Manati Medical Center
- Manatron
- Manatron
- Manchester Area Convention and Visitors Bureau
- Manchester Community College
- Manchester Community College
- Manchester VA Medical Center
- Mandarin Gems
- Manhattan Bagels - All stores
- Manhattan Borough President's Office
- Manhattan Chamber of Commerce
- Manhattan Convention and Visitors Bureau
- Manhatten Bagels
- Manning Regional Healthcare Center
- Manor Park Inc.
- ManPower
- Manuel Lujan Insurance, Inc.
- Manufactured Housing Institute
- Manufacturers Association of Northwest PA
- Manufacturers Bank and Trust Co.
- Manville Borough
- Maple Grove Hospital
- Marathon County Board
- Marble Institute of America