| Abbreviation | Definition |
|---|---|
| MSA(s) | metropolitan statistical area(s) |
| MSC | Mail Stop Code |
| MSCM | Mine Shaft Conveyance Monitoring |
| MSCO | Modeling and Simulation Coordination Office |
| MSDS | Material Safety Data Sheet |
| MSE | Mean Squared Error |
| MSE | Micro and Small Enterprises |
| MSEHPA | Model State Emergency Health Powers Act |
| MSG | Master Sergeant - Army |
| MSGR | Marine Security Guard Residence |
| MSgt | Master Sergeant - USAF, USMC |
| MSHA | Mine Safety and Health Administration |
| MSHFRC | Federal Mine Safety and Health Review Commission |
| MSI | Multiple Sources Of Income |
| MSII | Milestone I I |
| MSIS | Medicaid Statistical Information System |
| MSL | Minimum Subsistence Level |
| MSME | Micro, Small, and Medium Enterprises |
| MSMR | Medical Surveillance Monthly Report |
| MSNC | Mandatory Source National Contracts |