| Code | Name | Region |
|---|---|---|
| USNNB | Nash | TX |
| USNHC | Nash, Ellis | TX |
| US7AS | Nashotah | WI |
| USN2P | Nashport | OH |
| USN2S | Nashua | IA |
| USASH | Nashua | NH |
| USZNV | Nashville | AR |
| USN5V | Nashville | CA |
| USNHA | Naheola | AL |
| USNNH | Nahunta | GA |
| USNNK | Naknek | AK |
| USNOL | Nakolik River | AK |
| USNPA | Nampa | ID |
| USNNO | Nanticoke | MD |
| USNNC | Nanticoke | PA |
| USACK | Nantucket | MA |
| USNAE | Nanuet | NY |
| USAPC | Napa | CA |
| USWNA | Napakiak | AK |
| USNH8 | Napanoch | NY |
| USPKA | Napaskiak | AK |
| USNPV | Naperville | IL |
| USAPF | Naples | FL |
| USN6P | Naples | IL |
| USYUD | Naples | ME |
| USNPL | Naples | NC |
| USNPK | Naples | NY |
| USNPJ | Naples | TX |
| USUMU | Mustang | OK |
| USM7R | Mustang Ridge | TX |
| USYKC | Myakka City | FL |
| USDYF | Myers Flat | CA |
| USYES | Myerstown | PA |
| USMV5 | Myersville | MD |
| USXJL | Myrtle | MS |
| USMYR | Myrtle Beach | SC |
| USYTK | Myrtle Creek | OR |
| USGY7 | Myrtle Grove | FL |
| USMYG | Myrtle Grove | LA |
| USMFG | Myrtle Point | OR |
| USMYC | Mystic | CT |
| USM7O | Myton | UT |
| USNJB | Nabb | IN |
| USYNA | Naches | WA |
| USNAC | Naco | AZ |
| USOCH | Nacogdoches | TX |
| USKQV | Nags Head | NC |
| USN5H | Nahant | MA |
| USM9U | Murphysboro | IL |
| USQRU | Murray | IA |