I did some searching. I can't find much definitive information about the lt4114 modem other than the Spectre X2 product specs on HP's web site that states "Network interface - HP lt4114 LTE 4G Module for use on the Verizon LTE network". This doesn't say it will ONLY work on Verizon but it seems to imply that. This is also confirmed by the following thread from the HP Support Forum - http://h30434.www3.hp.com/t5/Window...0dx-Mobile-Broadband-Not-Working/td-p/4765724. Read it through until the end. Seems like you are out of luck using it other than on the Verizon network. To be certain, I would contact HP support for confirmation. Another option might be to buy a different HP modem that is supported on T-Mobile and replace the lt4114 one with it. You would have to feel comfortable opening the laptop but it should work provided you use the right drivers.