USTA Greater El Paso:  All zipcodes within El Paso County, Texas plus zipcodes of 88008 and 88063 in Dona Ana County in New Mexico.

USTA Southern New Mexico:  All zipcodes within Dona Ana County in New Mexico with the exception of zipcodes 88008 and 88063 and all zipcodes within Otero, Luna, Hidalgo, Grant and Sierra counties in New Mexico.

USTA Southeast New Mexico:  All zipcodes within Eddy, Lea, Roosevelt, Chaves, Curry, and Lincoln counties in New Mexico.

USTA Northern New Mexico:  All zipcodes within Bernalillo, Cibola, DeBaca, Guadalupe, McKinley, Quay, Socorro, Torrance, Valencia, Colfax, Harding, Los Alamos, Mora, Rio Arriba, San Juan, San Miguel, Santa Fe, Taos, Union and Sandoval counties in New Mexico.

USTA Southern Arizona:  All zipcodes within Pima County, plus Arizona City, Eloy, Mammoth, San Manual, and Oracle in Pinal County in Arizona.

USTA Southeastern Arizona (endorsed 12/99):  All zipcodes within Cochise County.

USTA Central Arizona:  All zipcodes within Maricopa County, plus Casa Grande, Coolidge, Apache Junction, Florence, Payson, Strawberry, Pine and City of Maricopa in Pinal County in Arizona.

USTA Northern Arizona:  All zipcodes within Yavapai County plus zipcodes of 86001, 86004, 86011, 86017, 86022, 86038 and 86046 in Coconino County in Arizona.

 
Following communtities are earmarked for future development:
More Northern Arizona (Page/Marble Canyon)
Eastern Arizona (Show Low, Globe, Morenci)
Western Arizona (Kingman, Lake Havasu)
Nogales/Rio Rico/Santa Cruz County
Yuma County
Thatcher & Safford in Graham County, Arizona