TAMPA, Fla. (WFLA) — Just like all old technology is phased out, the nation’s 3G network is approaching its end. For Americans with older phones that still run on 3G, it might be time to upgrade your phone, or face disconnection.

The National Association of State 911 Administrators issued a warning to consumers that anyone using old phones that rely on 3G service may need to switch to a newer device, or see their phones stop working. This includes other devices on the same network, like some medical devices, tablets, smart watches or home security systems, according to NASNA.

The 3G network has been active since 2001, one of multiple network improvements for cellular service introduced since 1979, with 1G.

Each generation after 1G has used new frequency bands and had higher data speeds, while being incompatible with older transmission technology, according to information from the International Telecommunication Union.

Now in 2021, 3G nears its retirement 20 years after launch.

“It is vitally important that the public be aware that national 3G networks will no longer work sometime early next year. These networks support older phones and devices that won’t work after the 3G network goes away” NASNA Director Harriet Rennie-Brown said.

Three major U.S. wireless carriers – AT&T, Verizon and T-Mobile – have all announced a plan to discontinue 3G service as they transition to 4G and 5G in 2022.

The Federal Communications Commission has also addressed this transition, telling users that mobile phones older than a few years may need to be upgraded to avoid losing service. All three mobile carriers will shut off 3G by the end of 2022, but some will stop earlier in the year.

The FCC broke down the cut-off times for the companies in an announcement earlier in the year.

AT&T announced it will shut off its 3G network in February 2022, while T-Mobile will close off the Sprint 3G CDMA network on March 31 and the Sprint 4G LTE network by June 30, 2022. Both systems facing shutdown were absorbed in the T-Mobile/Sprint merger of April 2020.

T-Mobile will shut down its own 3G UMTS network by July 1, 2022, but has not announced a cut-off date for its 2G network, according to the FCC.

Verizon will be the last of the big three networks to shut down 3G service, with an expected cut-off of Dec. 31, 2022. The FCC warns that other carriers may be affected by the other companies turning off 3G, as they use their networks for service.

“Many carriers, such as Cricket, Boost, Straight Talk, and several Lifeline mobile service providers, utilize AT&T’s, Verizon’s, and T-Mobile’s networks,” the FCC said in its announcement.

For low-income residents, NASNA and the FCC encourage checking for eligibility in the Lifeline Program, a federal communications initiative aimed at assisting with providing low-cost service or discounts for phone and internet service or bundles.