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. Customers who were still on T-Mobile's 2G network were warned well ahead of time about the shutdown and given time to transition. 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.