| Abbreviation | Definition |
|---|---|
| MART | Minnesota Association of Rogue Taxidermists |
| MAS | Multicultural Association of Students |
| MASA | Magnolia Area Softball Association |
| MASA | Maharashtra Association of School of Architecture |
| MASA | Medical Air Services Association |
| MASA | Medical Association of the State of Alabama |
| MASA | Michigan Association of School Administrators |
| MASA | Michigan Association of Superintendents Administrators |
| MASA | Multi Asian Student Association |
| MASB | Michigan Association of School Boards |
| MASC | Massachusetts Association of School Committees |
| MASE | Maine Association of Site Evaluators |
| MASHA | Metro Atlanta Street Hockey Association |
| MASHA | Mines and Aggregates Safety and Health Association |
| MASL | Maryland Association of School Librarians |
| MASL | Missouri Association of School |
| MASL | Missouri Association of School Librarians |
| MASO | Malaysian Association for the Study of Obesity |
| MASOM | Midwest Association of Shia Organized Muslims |
| MASP | Maine Association of School Psychologists |