| MHSAA | Madison High School Alumni Association (Madison, TN 37115) 
| Others |
| MHSAA | Metro High School Activities Association
| Others |
| MHSAA | Metropolitan High School Activities Association
| Others |
| MHSAA | Michigan High School Athlete Association
| Others |
| MHSAA | Michigan High School Athletic Association
| Others |
| MHSAA | Milton Hershey School Alumni Association
| Others |
| MHSAA | Mississippi High School Activities Association
| Others |
| MHSAA | Mississippi High School Athletic Association
| Others |
| MHSAA | Mississippi High School Athletics Association
| Others |
| MHSAA | Missouri High School Athletic Association
| Others |