| Abbreviation | Definition |
|---|---|
| MTOA | Midland Tree Officers Association |
| MTOA | Midwest Tactical Officer Association |
| MTOA | Midwest Tactical Officers Association |
| MTOA | Mississippi Tactical Officers Association |
| MTRA | Michigan Therapeutic Recreation Association |
| MTRA | Midwest Trail Riders Association |
| MTRA | Minnesota Therapeutic Recreation Association |
| MTRA | Minnesota Trail Riders Association |
| MTRA | Money Transmitter Regulators Association |
| MTTA | Massachusetts Trowel Trades Association |
| MTTA | Montana Tow Truck Association |
| MTTA | Mount Tahoma Trails Association |
| MUA | Moodle Users Association |
| MUAA | Marian University Alumni Association |
| MUAA | Marquette University Alumni Association |
| MUAA | Miami University Alumni Association |
| MUBA | Maumee Uptown Business Association |
| MUCA | Minnesota Utility Contractors Association |
| MUFASA | Montclair Unified Filipino American Student Association |
| MUSA | Marshall United Soccer Association |