| Multimission Archive at Space Telescope | Academic & Science |
| Master of Advanced Study | Academic & Science |
| Maritime Academy of Science and Technology | Academic & Science |
| Maryland Association of Science Teachers | Business |
| Managemement Aptitude and Skill Test | Business |
| Modular Aluminium Set Technology | Business |
| Micro Autonomous System Technologies | Business |
| Management Analysis and Strategic Thinking | Business |
| Mountain Area Safety Taskforce | Community |
| Mathematics And Science Teaching | Community |
| Manitoba Association of School Trustees | Community |
| Mandatory After School Tutoring | Community |
| Massachusetts Association of Science Teachers | Community |
| Metropolitan Ambulance Services Trust | Community |
| Math And Science Tutoring | Community |
| Multicultural Assessment and Services Team | Community |
| Microsoft Azure Support Team | Computing |
| Master of Architecture In Suburb & Town Design | Educational Degree |
| Mikulski Archive for Space Telescopes | General |
| Michigan Alcoholism Screening Test | General |
| Mandatory Alcohol Server Training | General |
| Masters And slaves Together | General |
| Module Advanced Setup Tool | General |
| Minnesota Agricultural Student Trainee | General |
| Mooring And Status Tunnel | General |
| Motif Alignment and Search Tool | General |
| Multi Axial Subassemblage Testing | General |
| Merklized Abstract Syntax Trees | General |
| Merkelized Abstract Syntax Trees | General |
| Master Automotive Service Technician | General |
| Museo del Automovil de Santa Teresita | General |
| Master Automotive Service Technology | General |
| Michigan Alcohol Screening Test | Governmental |
| Mutual Aid Support Team | Governmental |
| Midwest Alliance of Sovereign Tribes | Governmental |
| Minimal Access Spinal Technologies | Medical |
| mastitis | Medical |
| mastoid | Medical |
| Military Anti Shock Trousers | Medical |
| mitochondrial aspartate aminotransferase | Medical |
| mitochondrial AST | Medical |
| Motion Artifact Suppression Technique | Medical |
| mRNA accessible site tagging | Medical |
| Multi-Agency Support Team | Medical |
| Multi-Attitude Suicide Tendency Scale | Medical |
| Mobile Ashore Support Terminal | Military and Defence |
| Military Assistance In Safety and Traffic | Military and Defence |
| Maximum Aircrew Stress Tolerance | Military and Defence |
| Mobile Army Surgical Team | Military and Defence |
| Military Assistance To Safety and Traffic | Military and Defence |
| Monitoring and Support Time | Networking |
| Medical Anti-shock Trousers | Space Science |
| Micro Autonomous Systems and Technology | Technology |
| Maritime and Science Technology | Technology |
| Math and Science Technology | Technology |
| Marine Advanced Systems and Technology | Technology |