From Sony's Whitepapers
D5803
UMTS HSPA+ 850 (Band V), 900 (Band VIII), 1700 (Band IV), 1900 (Band II), 2100 (Band I) MHz
GSM GPRS/EDGE 850, 900, 1800, 1900 MHz
LTE (Bands 1, 2, 3, 4, 5, 7, 8, 13, 17, 20)
D5833
UMTS HSPA+ 850 (Band V), 900 (Band VIII), 1900 (Band II), 2100 (Band I) MHz
GSM GPRS/EDGE 850, 900, 1800, 1900 MHz
LTE (Bands 1, 3, 5, 7, 8, 28)
TD LTE Band 40
So yes, D5803 for AT&T. Clove sells the D5803 so for those who want it in the States and are with AT&T, I'd suggest you take advantage of the low price promotion + free accessories. I would not expect this phone to arrive on any US carrier and from Sony's website it will be considerably more expensive.