AT&T: January 2022
3G Shutdown Update: Carriers Sunsetting 3G to Make Room for 5G
Carriers are sunsetting older network technologies like 3G to make more room for 4G/LTE and 5G.
Voice service on LTE and 5G is fundamentally different than 3G and requires a phone that supports it.
Those with older devices that only support 3G voice should be planning on upgrading.