| Massachusetts State College Association | Academic & Science |
| Mobilized Soil Conductivity Assessment | Academic & Science |
| Mount Saint Charles Academy | Academic & Science |
| Massachusetts Systems Contractors Association | Business |
| M S Carriers, Inc. | Business |
| Mechanicsburg Supply Corps Association | Business |
| Mechanical Service Contractors of America | Business |
| Mid South Cartoonists Association | Community |
| Minnesota Shopping Center Association | Community |
| Michigan School Counselor Association | Community |
| Missouri School Counselor Association | Community |
| Mid South Compensation Association | Community |
| Minnesota School Counselors Association | Community |
| Maryland Summer Center for the Arts | Community |
| Missouri State Chiropractors Association | Community |
| Maryland School Counselor Association | Community |
| Master Source Code Agreement | Computing |
| Marie Skłodowska Curie actions | General |
| Minnesota State Chess Association | General |
| Media Solution Center America | General |
| M Special Car Armoring | General |
| Missing Cargo | General |
| McCarthy Scales of Children's Abilities | General |
| Marque Sports Car Association | General |
| Midsouth Sprint Car Association | General |
| Motor Sports Club of America | General |
| Maremma Sheepdog Club of America | General |
| Military Support to Civilian Authorities | Governmental |
| My Service Canada Account | Governmental |
| Military Support to Civil Authorities | Governmental |
| Multiple Sclerosis Center of Atlanta | Medical |
