T-Mobile retired its 2G GSM network on Monday, August 3, which means all three major carriers in the United States have now ended 2G service.

T-Mobile kept its 2G network active because it still had some legacy customers who were using it. Some customers visiting the United States and using international roaming carrier agreements for connectivity also needed 2G for voice calling, but T-Mobile worked with carriers globally to prepare for the end of its 2G network.

Customers who were still on T-Mobile's 2G network were warned well ahead of time about the shutdown and given time to transition. Smartphones, alarm panels, payment terminals, and other IoT accessories that used 2G will no longer function.

AT&T ended support for 2G almost a decade ago in 2017, and Verizon stopped supporting 2G in 2020. Now that no carriers in the U.S. support 2G, legacy devices like the original iPhone will not be able to connect to any cellular network. The iPhone technically lost cellular support in 2017 when AT&T sunset its 2G network, and now the last workaround is gone.

All three carriers also ended support for 3G back in 2022, and have also abandoned early LTE iPhones without VoLTE support.

Source: Macrumors