| Code | Name | Region |
|---|---|---|
| USTYO | Troy | VA |
| USII9 | Trilla | IL |
| USAK4 | Trinidad | CA |
| USTAD | Trinidad | CO |
| US9TD | Trinidad | TX |
| USQTI | Trinity | AL |
| USTT7 | Trinity | MS |
| USTIR | Trinity | NC |
| USINZ | Trinity | TX |
| USTYK | Trinity Park | NC |
| USTNG | Trion | GA |
| USTIP | Tripp | SD |
| USTRH | Trona | CA |
| USTR7 | Trophy Club | TX |
| USTRO | Trotwood | OH |
| USTXP | Troup | TX |
| USTZQ | Trout Creek | MT |
| USTCR | Trout Creek | NY |
| USTQU | Trout Lake | WA |
| USTRR | Trout River | NY |
| USTTD | Troutdale | OR |
| UST5N | Trenton | ME |
| USXNG | Trenton | MI |
| USTRX | Trenton | MO |
| USTNZ | Trenton | NC |
| USTTN | Trenton | NJ |
| USTNX | Trenton | OH |
| USXTO | Trenton | SC |
| USTRN | Trenton | TN |
| UST6N | Trenton | TX |
| USTR5 | Trenton | UT |
| US8YI | Tres Pinos | CA |
| US8TR | Trevett | ME |
| USZJB | Trevilians | VA |
| USTVO | Trevor | WI |
| USTVR | Trevorton | PA |
| USTVS | Trevose | PA |
| USTDP | Triadelphia | WV |
| USTNV | Triangle | VA |
| USYTC | Tri-cities | WA |
| USXNJ | Travelers Rest | SC |
| USTVY | Traver | CA |
| USTVC | Traverse City | MI |
| USVFB | Travis Air Force Base | CA |
| USEUA | Treasure Island | FL |
| USTSU | Treasure Island/los Angeles | CA |
| USTRP | Tree Point | AK |
| USTG8 | Trego | MT |
| USTR9 | Tremont | IL |
| USTMX | Tremont | MS |