T-Mobile CEO Mike Sievert is looking to expand the company further into fiber internet service without making major capital investments. (GeekWire File

T-Mobile US is sneaking into the cable industry’s backyard. The second-biggest cellphone carrier by subscribers has pieced together at least five partnerships with fiber-optic internet providers that could serve millions of customers in the coming years.

Despite the potential regulatory hurdles, T-Mobile appears to be in major expansion mode. Since 2022, it has purchased Mint Mobile, Ultra Mobile and Plum, all part of parent company Ka'ena Corporation and Play Octopus, a rideshare advertising network.

T-Mobile hasn't had the smoothest years in recent memory, and in some people's eyes, has even become the villain of the wireless industry it once fought so hard to defend consumers from. Of course, there are a lot of different factors that contribute to its recent image change,