| | Taylor County | TX | 48441 | | Abilene, TX 10180 | Abilene-Sweetwater, TX 101 | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=TaylorCounty+TX |
| | Terrell County | TX | 48443 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=TerrellCounty+TX |
| | Terry County | TX | 48445 | | | | | nonmetro county (rural) | mining-dependent | https://maps.google.com/?q=TerryCounty+TX |
| | Throckmorton County | TX | 48447 | | | | | nonmetro county (rural) | farm-dependent | https://maps.google.com/?q=ThrockmortonCounty+TX |
| | Titus County | TX | 48449 | | Mount Pleasant, TX 34420 | | Central | nonmetro county (rural) | manufacturing-dependent | https://maps.google.com/?q=TitusCounty+TX |
| | Tom Green County | TX | 48451 | | San Angelo, TX 41660 | | Central | metro county (urban) | nonspecialized | https://maps.google.com/?q=TomGreenCounty+TX |
| | Travis County | TX | 48453 | | Austin-Round Rock-San
Marcos, TX 12420 | | Central | metro county (urban) | federal/state
government-dependent | https://maps.google.com/?q=TravisCounty+TX |
| | Trinity County | TX | 48455 | | | | | nonmetro county (rural) | recreation | https://maps.google.com/?q=TrinityCounty+TX |
| | Tyler County | TX | 48457 | | | | | nonmetro county (rural) | federal/state
government-dependent | https://maps.google.com/?q=TylerCounty+TX |
| | Upshur County | TX | 48459 | | Longview, TX 30980 | | Outlying | metro county (urban) | nonspecialized | https://maps.google.com/?q=UpshurCounty+Texas |