| Code | Name | Region |
|---|---|---|
| USAMF | Amagansett | NY |
| USUBG | Amana | IA |
| USAP4 | Amanda Park | WA |
| USAGY | Amargosa Valley | NV |
| USAMA | Amarillo | TX |
| USAMM | Amasa | MI |
| US2AA | Ambia | IN |
| USABL | Ambler | AK |
| USALN | Alton | IL |
| USA4L | Alton | MO |
| USKLQ | Alton | NY |
| USONB | Alton | VA |
| USA7B | Alton Bay | NH |
| USAZQ | Altoona | FL |
| USNOF | Altoona | IA |
| USAOO | Altoona | PA |
| USAZP | Altoona | WI |
| USAXU | Altura | MN |
| USZIF | Alturas | CA |
| USAZX | Altus | AR |
| USLTS | Altus | OK |
| USQAB | Alum Bank | PA |
| USAZT | Alum Rock | CA |
| USALF | Alva | FL |
| USXAK | Alva | OK |
| USAV6 | Alva | WY |
| USAV8 | Alvada | OH |
| USAZB | Alvarado | CA |
| USTUU | Alta | WY |
| USTAJ | Alta Loma | CA |
| USAJM | Alta Loma | TX |
| USAV3 | Alta Vista | KS |
| USAZA | Altadena | CA |
| USUBD | Altamahaw | NC |
| USAZN | Altamont | IL |
| USA7L | Altamont | KS |
| USZTM | Altamont | NY |
| USAM7 | Altamont | TN |
| USTMO | Altamont | UT |
| USASP | Altamonte Springs | FL |
| USPSQ | Altapass | NC |
| USATV | Altavista | VA |
| USGUA | Altenburg | MO |
| USA7H | Altha | FL |
| USTMR | Altheimer | AR |
| USAOQ | Alto | GA |
| USAO2 | Alto | MI |
| USYW9 | Alto | TX |
| USA4P | Alpena | SD |
| USAJQ | Alpha | IL |