| Code | Name | Region |
|---|---|---|
| USXTV | Three Rivers | TX |
| UST3W | Three Way | TN |
| USTH6 | Throckmorton | TX |
| USTPY | Throop | PA |
| USTH4 | Thurmond | NC |
| USURM | Thurmont | MD |
| USTQS | Thurston | NE |
| USXTN | Tiburon | CA |
| USTIC | Ticonderoga | NY |
| USTDE | Tierra Verde | FL |
| US3TF | Tiffin | IA |
| USTFN | Tiffin | OH |
| USTMA | Tifton | GA |
| USTID | Tigard | OR |
| USTG9 | Tiger | GA |
| USTGR | Tigerton | WI |
| USTGL | Tignall | GA |
| USTIJ | Tijeras | NM |
| USKTH | Tikchik | AK |
| UST4D | Tilden | NE |
| USTH5 | Thornton | NH |
| USTWV | Thornton | WV |
| USTVH | Thornville | OH |
| USNYT | Thornwood | NY |
| USTRF | Thorofare | NJ |
| USTP6 | Thorp | CO |
| USTJP | Thorp | WA |
| USTQP | Thorp | WI |
| USTB2 | Thorsby | AL |
| USJTO | Thousand Oaks | CA |
| USUNG | Thousand Palms | CA |
| USTH2 | Thrall | TX |
| USTHE | Three Bridges | NJ |
| USTFK | Three Forks | MT |
| USQTF | Three Forks Junction | MT |
| USQTK | Three Lakes | WI |
| USOI7 | Three Oaks | MI |
| USTR8 | Three Rivers | CA |
| USTRJ | Three Rivers | MA |
| USHAI | Three Rivers | MI |
| USTPF | Thompson | IA |
| USTO5 | Thompson | MO |
| USTPJ | Thompson | ND |
| USTPS | Thompson | OH |
| USTHF | Thompson Falls | MT |
| USTHM | Thompsonfield | MO |
| UST9H | Thompsons | TX |
| USTVT | Thompsons Station | TN |
| USTPW | Thompsontown | PA |
| USTHL | Thompsonville | MI |