| Code | Name | Region |
|---|---|---|
| USABW | Atlasburg | PA |
| USATT | Atmautluak | AK |
| USAMK | Atmore | AL |
| USAOD | Atoka | OK |
| USAK2 | Atoka | TN |
| USATK | Atqasuk | AK |
| USATR | Atreco | TX |
| USAAA | Attalla | AL |
| USAPS | Attapulgus | GA |
| USAJZ | Attica | IL |
| USA2Q | Attica | IN |
| USIAX | Attica | KS |
| USAQ7 | Attica | NY |
| USXTC | Attica | OH |
| USAOM | Attleboro | MA |
| USA6M | Attleboro Falls | MA |
| USATU | Attu Island | AK |
| USATZ | Atwater | CA |
| USAIS | Atkins | VA |
| US3AI | Atkinson | IL |
| USZAS | Atkinson | NC |
| USAN3 | Atkinson | NE |
| USTKD | Atkinson | NH |
| USA2N | Atlanta | CA |
| USATL | Atlanta | GA |
| USAZI | Atlanta | IL |
| USTLN | Atlanta | IN |
| USQJA | Atlanta | MI |
| USQAN | Atlanta | NE |
| USTAT | Atlanta | TX |
| USAIO | Atlantic | IA |
| USAT5 | Atlantic | NC |
| USAC6 | Atlantic | PA |
| USNIC | Atlantic | VA |
| USQAT | Atlantic Beach | FL |
| USTBH | Atlantic Beach | NC |
| USZNB | Atlantic Beach | NY |
| USAIY | Atlantic City | NJ |
| USATQ | Atchison | KS |
| USAGL | Atglen | PA |
| USTHN | Athena | OR |
| USATA | Athens | AL |
| USAHN | Athens | GA |
| USAZH | Athens | IL |
| USQAH | Athens | ME |
| USAN4 | Athens | MI |
| USATB | Athens | NY |
| USATO | Athens | OH |
| USATN | Athens | PA |
| USMMI | Athens | TN |