| Code | Name | Region |
|---|---|---|
| USAPA | Alpha | NJ |
| USALP | Alpha | OH |
| USAAI | Alpharetta | GA |
| USAPL | Alpine | AL |
| USAPY | Alpine | NJ |
| USALE | Alpine | TX |
| USAP2 | Alpine | UT |
| USAP5 | Alpine | WY |
| USAWU | Alpine Meadows | CA |
| USZJI | Alpine, Los Angeles | CA |
| USJIN | Alpine, San Diego | CA |
| USAEN | Alsen | NY |
| USAY4 | Alsey | IL |
| USUBC | Alsip | IL |
| USAFA | Alstead | NH |
| USAJL | Alta | CA |
| USW82 | Alta | IA |
| USXBO | Alta | UT |
| USAIH | Alliance | OH |
| USIXS | Allison | TX |
| USALK | Allison Park | PA |
| USAOY | Alloy | WV |
| USXBE | Allston | MA |
| USAY3 | Allyn | WA |
| USRAA | Alma | AR |
| USAM2 | Alma | CO |
| USAMQ | Alma | GA |
| USAM6 | Alma | KS |
| USAMN | Alma | MI |
| USXAM | Alma | WI |
| USN6A | Almena | WI |
| USAO5 | Almond | WI |
| USATJ | Almont | MI |
| US8AL | Alna | ME |
| USAHA | Aloha | OR |
| USZON | Alorton | IL |
| USA3P | Alpaugh | CA |
| USAPN | Alpena | MI |
| USAPK | Allen Park | MI |
| USGKE | Allendale | MI |
| USUAZ | Allendale | NJ |
| USEDL | Allendale | SC |
| USNUS | Allenhurst | NJ |
| USAJP | Allenport | PA |
| USATX | Allenstown | NH |
| USA4V | Allensville | PA |
| USAWF | Allensworth | CA |
| USQWU | Allenton | NC |
| USZAG | Allenton | WI |
| USAEW | Allentown | NJ |