| MTSA | Major Transit Station Area 
| Others |
| MTSA | Management Technology Services Alliance
| Others |
| MTSA | Manchester Township Soccer Association
| Others |
| MTSA | Maritime Transportation Safety Act
| Others |
| MTSA | Maritime Transportation Security Act
| Others |
| MTSA | Mask Tensorized Self Attention
| Others |
| MTSA | Master of Transportation Safety Administration
| Others |
| MTSA | McCandless Township Sanitary Authority
| Others |
| MTSA | Metropolitan Travel Survey Archive
| Others |
| MTSA | Michigan Taiwanese Student Association
| Others |
| MTSA | Michigan Transition Services Association
| Others |
| MTSA | Middle Tennessee School of Anesthesia
| Others |
| MTSA | Middle Tennessee Suzuki Association
| Others |
| MTSA | Midwest Travel Suppliers Association
| Others |
| MTSA | Military Training Specific Allotment
| Others |
| MTSA | Minnesota Transport Services Association
| Others |
| MTSA | Missile Technician Seaman Apprentice
| Others |
| MTSA | Mobile Telecommunications Sourcing Act
| Others |
| MTSA | Monsanto Technology Stewardship Agreement
| Others |
| MTSA | Multi Tissue Segmentation Algorithm
| Others |
| MTSA | Multi Tower Solar Array
| Others |