| Code | Name | Region |
|---|---|---|
| USM4C | Marble City | OK |
| USMFA | Marble Falls | TX |
| USZMB | Marble Hill | GA |
| USMQQ | Maple City | MI |
| USMPG | Maple Grove | IL |
| USXMG | Maple Grove | MN |
| USMGZ | Maple Grove | OH |
| USMAP | Maple Heights | OH |
| USMPU | Maple Hill | KS |
| USMIM | Maple Island | MN |
| USYWO | Maple Lake | MN |
| USMEP | Maple Park | IL |
| USMP4 | Maple Plain | MN |
| USXJA | Maple Shade | NJ |
| USMV7 | Maple Valley | WA |
| USAJV | Maplesville | AL |
| USXIS | Mapleton | IL |
| USMPM | Mapleton | ME |
| USXUY | Mapleton | MN |
| USNDK | Mapleton | ND |
| USM4P | Mapleton | OR |
| USNZX | Mapleton | TX |
| USM9T | Mapleton | UT |
| USNSU | Mansura | LA |
| USATI | Mantachie | MS |
| USMTA | Manteca | CA |
| USMTZ | Mantee | MS |
| USMTR | Manteno | IL |
| USMEO | Manteo | NC |
| USNTJ | Manti | UT |
| USN6J | Mantoloking | NJ |
| USIZM | Manton | MI |
| USHY3 | Mantorville | MN |
| USQMU | Mantua | NJ |
| USMT9 | Mantua | OH |
| USMAV | Manvel | TX |
| USMWP | Manver | PA |
| USJVI | Manville | NJ |
| USAVR | Manville | RI |
| USNMY | Many | LA |
| USF8M | Many Farms | AZ |
| USM5Z | Manzanola | CO |
| USZPU | Maple Bluff | WI |
| USNSV | Mannsville | NY |
| USKMO | Manokotak | AK |
| USZMA | Manor | GA |
| USMZ9 | Manor | PA |
| USMAQ | Manor | TX |
| USMRA | Manorville | NY |
| USMQ3 | Manquin | VA |