| Code | Name | Region |
|---|---|---|
| USIET | Marietta | FL |
| USMGE | Marietta | GA |
| UST6T | Marietta | IL |
| USRTT | Marietta | OH |
| USMIR | Marietta | OK |
| USMPD | Marietta | PA |
| USRTA | Marietta | SC |
| USDXM | Marin City | CA |
| USMAK | Marina | CA |
| USMDX | Marina Del Rey | CA |
| USMOY | Marinette | WI |
| USMGU | Maringouin | LA |
| USPU8 | Marion | AL |
| USM55 | Marble Hill | MO |
| US4MH | Marblehead | IL |
| USMH2 | Marblehead | MA |
| USHD9 | Marblehead | OH |
| USMOV | Marceline | MO |
| USMU6 | Marcellus | MI |
| USZLS | Marcellus | NY |
| USRSY | March Air Reserve Base | CA |
| USMRK | Marco Island | FL |
| USMAH | Marcus Hook | PA |
| USZAY | Marcy | NY |
| USMI8 | Mare Island | CA |
| USMGO | Marengo | IA |
| USREG | Marengo | IL |
| USAEG | Marengo | IN |
| USM2A | Marengo | OH |
| USMRF | Marfa | TX |
| USZEU | Margaretville | NY |
| USMGT | Margate | FL |
| USRTE | Marguerite Bay | AK |
| USMPX | Mapleville | RI |
| USNPQ | Maplewood | MN |
| USMW2 | Maplewood | MO |
| USMPW | Maplewood | NJ |
| USMEK | Mappsville | VA |
| USMQO | Maquoketa | IA |
| USMVA | Mar Vista | CA |
| USMZJ | Marana | AZ |
| USMTH | Marathon | FL |
| USOM9 | Marathon | IA |
| USNYA | Marathon | NY |
| USM7T | Marathon | TX |
| USMHH | Marathon | WI |
| USMX2 | Marble | CO |
| USARQ | Marble | NC |
| USNN9 | Marble | PA |
| USMYH | Marble Canyon | AZ |