| Abbreviation | Definition |
|---|---|
| McREL | Mid-Continent Regional Educational Laboratory |
| MCS | Mathematical and Computer Sciences |
| MCS | Modified Cornell System |
| MCSE | Multiple Choice Selection Expert |
| MCTA | Midwest Chinese Teachers' Alliance |
| MCU | Mastery Check Up |
| MD | Mathematically Deficient |
| MD | Medium to Difficult |
| MD | Mentally Deficient |
| MD | Mentally Disabled |
| MD | Moby Dick |
| MDE | Michigan Department of Education |
| MDE | Minnesota Department of Education |
| MDEA | Mt Diablo Education Association |
| MDEC | Mid Dakota Education Cooperative |
| MDH | Madeleine D'Houet |
| MDIE | Mater Dei Institute of Education |
| MDK-12 | Maryland K-12 Community |
| MDL | Multiple Disciplinary Learning |
| MDLA | Maryland Distance Learning Association |