| MChD | Magister Chirurgiae Dentium, Master of Dental Surgery
| Others |
| MCHD | Marion County Health Department
| Others |
| MCHD | Marion County Health Department's
| Others |
| MCHD | Mini Critical Hit Device
| Others |
| MCHD | Mobile County Health Department
| Others |
| MCHD | Monmouth County Health Department
| Others |
| MCHD | Monongalia County Health Department
| Others |
| MCHD | Monterey County Health Department
| Others |
| MCHD | Montessori Children's House of Durham
| Others |
| MCHD | Montgomery County Health Department
| Others |
| MCHD | Montgomery County Hospital District
| Others |
| MCHD | Moore County Hospital District
| Others |
| MCHD | Mountain Communities Healthcare District
| Others |
| MCHD | Multnomah County Health Department
| Others |