Right now, the Verizon iPhone 5 will only register the 4G 1900 Mhz (Band 25) which is also being used by T-Mobile in ONLY a selected markets. I live in Phoenix and it's sporadic 3G only. No LTE. I don't think the iPhone 5 will ever use T-Mobile's prospective LTE capabilities. MacRumors has a report on prior Apple approval of LTE feature.