| Abbreviation | Definition |
|---|---|
| MSCI | Michigan Speech Coaches, Incorporated |
| MSDA | A Midwest Scrap Dealers Association |
| MSDA | Maryland Sporting Dog Association |
| MSDA | Minnesota Security Dealers Association |
| MSDA | Minnesota Stamp Dealers Association |
| MSDA | Minority Student Dental Association |
| MSEC | Mountain States Employers Council |
| MSFA | Maryland State Firemen's Association |
| MSHA | Mississppi Speech-Language-Hearing Association |
| MSIA | Medical Software Industry Association |
| MSIA | Michigan Snowsports Industries Association |
| MSIA | Minnesota Self Insurers Association |
| MSIA | Minnesota Storm Intercept Association |
| MSN | Malaysian Society of Nephrology |
| MSNA | Minnesota School Nutrition Association |
| MSPA | Maryland School Psychologists Association |
| MSPA | Mid South Paintball Association |
| MSPA | Mystery Shopping Providers Association |
| MSPC | Midwest Society of Professional Consultants |
| MSS | Manufacturers Standardization Society |