| Acronym | Definition |
|---|
| MTSS | Multi-Tiered System of Support (education) |
| MTSS | Ministerio de Trabajo y Seguridad Social (Spanish) |
| MTSS | Midwest Teen Sex Show (sex education video series) |
| MTSS | Medial Tibial Stress Syndrome (lower leg injury) |
| MTSS | Modified Total Sharp Score (radiography) |
| MTSS | Military Training Service Support |
| MTSS | Money Transfer Service Scheme (India) |
| MTSS | Media Technology Support Services (Pennsylvania State University) |
| MTSS | Manufacturing Test Software Solution |
| MTSS | Main Traffic Signal System (transportation) |
| MTSS | Material Toxicity Summary Sheet (product safety) |
| MTSS | Managed Tiered Security Service |
| MTSS | MAGTF (Marine Air-Ground Task Force) Training Systems Support (US Marine Corps) |