| Medical Student Interactive Site | Academic & Science |
| Medical School Information System | Academic & Science |
| McKinsey Students In Society | Academic & Science |
| Master of Science in Information Science | Academic & Science |
| MS Student Information System | Academic & Science |
| Medicaid and Statistical Information System | Academic & Science |
| Masters of Science in Information Systems | Academic & Science |
| Master of Science in Information Sciences | Academic & Science |
| Master of Science in Information Security | Academic & Science |
| Master of Science Information Systems | Academic & Science |
| Master of Science in Interdisciplinary Studies | Academic & Science |
| Mountain State Information Systems | Business |
| Main Street Internet Service | Business |
| Morris Sallick Industrial Supplies, Inc. | Business |
| Management Science and Information Systems | Business |
| Mississippi Student Information System | Community |
| Milwaukee Spanish Immersion School | Community |
| Master of Science In Information Systems | Educational Degree |
| Maple Syrup Injected Sausage | General |
| Mobility Support Intermediate System | General |
| Maryland Safety Inspection System | General |
| MSHA Standardized Information System | General |
| Master S in Information Systems | General |
| Marine Safety Information System | Governmental |
| Medicaid Statistical Information System | Governmental |
| Medical School Information Services | Medical |
| Medical School Information Systems | Medical |
| Modeling and Simulation Information System | Military and Defence |
| Mass Spectrometer and Incoherent Scatter | Physics Related |
| Man-systems Integration Standards | Space Science |
| Mobile Station International Subscriber | Telecommunication |
