| Code | Name | Region |
|---|---|---|
| USMBQ | Manhattan Beach | CA |
| USMNH | Manhattan/new York | NY |
| USMHF | Manheim | PA |
| USMNZ | Manassas | VA |
| USKMK | Manassas Park | VA |
| USMEE | Manatee | FL |
| USMWW | Manawa | WI |
| USMY2 | Manayunk | PA |
| USM9A | Mancelona | MI |
| USM2U | Manchaug | MA |
| USM3T | Manchester | CA |
| USMNE | Manchester | CT |
| USMHI | Manchester | GA |
| USMNX | Manchester | IA |
| USMCX | Manchester | KY |
| USZRM | Manchester | MA |
| USZMN | Manchester | MD |
| USMR7 | Manchester | ME |
| USMPC | Manchester | MI |
| USMNY | Manchester | MO |
| USMHT | Manchester | NH |
| USNMJ | Manchester | NJ |
| USM7W | Manchester | NJ |
| USVVM | Malvern | AL |
| USMV6 | Malvern | AR |
| US3MV | Malvern | IA |
| USMVR | Malvern | OH |
| USMWN | Malvern | PA |
| USMA7 | Malvern | TX |
| USUQJ | Mamaroneck | NY |
| USZMH | Mammoth | CA |
| USMMH | Mammoth Lakes | CA |
| USM3S | Mammoth Spring | AR |
| USMUX | Mamou | LA |
| USVMA | Man | WV |
| USAAW | Manahawkin | NJ |
| USM2K | Manakin | VA |
| US9MT | Manakin-sabot | VA |
| USMQN | Manalapan | FL |
| USAPZ | Manalapan | NJ |
| USZMQ | Manasquan | NJ |
| USMX4 | Manassa | CO |
| USXM2 | Manassas | GA |
| USMG5 | Malaga | WA |
| USMKF | Malakoff | TX |
| USM24 | Malcolm | NE |
| USGMM | Malcom | IA |
| USXII | Malden | MA |
| USMAW | Malden | MO |
| USD88 | Malden | WA |