Personal testimonial, I have been using this phone which only supports bands 2, 4, and 12 for around 3 years now (too many in my opinion) on T-Mobile. I don't have experience with phones that use bands 66 and 71, but my phone works great throughout the cities and the northern part of Minnesota, and I don't remember having any issues when traveling around the states. Of course, this is my personal experience, and your area's coverage will very. I'm just saying I personally haven't have any problems while using my phone on their network.