T-Mobile US 2G GSM

As of August 3rd, 2026, T-Mobile US has shut down their 2G GSM network.

After years of phasing out their older 2G GSM network, T-Mobile US began its nationwide GSM shutdown on 8/3/2026, with some areas maintaining service until 8/4/2026. The shutdown has been finalized on 8/11/2026, with the shutdown of GSM in Spokane, Washington: the final coverage area.

What this means:

Since AT&T shut off its GSM network in 2017, T-Mobile has been the only nationwide operator to maintain its legacy 2G service. For a while, this was not an issue due to the presence of 3G (UMTS & CDMA2000) networks in the United States. However, in 2022, operators began sunsetting their 3G networks in favor of modern 4G and 5G services. The absense of 3G meant that T-Mobile's 2G GSM service was now the final legacy, circuit-switched network available in the United States.

Now that T-Mobile has shut down the final 2G network, the United States is now officially a 4G/5G only country, meaning that all calls are now routed over VoLTE or VoNR, and many older devices have permanently lost service.

History and Decay of T-Mobile GSM:

In 1994, VoiseStream Wireless (later purchased by Deutsche Telekom, and rebranded to T-Mobile US) was established as a regional cellular carrier in the United States, and launched its initial 2G GSM network in 1996 on the PCS (1900 MHz) band.

In its peak, T-Mobile's GSM network occupied over 10x10 MHz of dedicated PCS spectrum. This allowed T-Mobile to utilize several BCCH (beacon) channels for minimal spectrum reuse, which insured that towers did not interfere with each other. T-Mobile also utilized many hopping TCH (traffic) channels, which provided additional capacity to users for both calls and data.

Over the years, T-Mobile's cellular service expanded to focus on newer technologies, such as 3G (UMTS) and 4G (LTE). These changes led to gradual, largely undetectable capacity adjustments to GSM over the years, as more users migrated to newer services.

As early as 2013, T-Mobile began refarming its PCS spectrum to make room for its new 4G LTE services. Depending on availability of spectrum in a market, GSM's spectrum allocation would be changed in order to support a wideband LTE carrier. Changes included less hopping channels, and tighter spectrum reuse patterns, which would affect GSM's total capacity.

Around this time, T-Mobile began to phase out its use of Full Rate calls as part of their refarming efforts. Instead, T-Mobile started forcing users to use the Half Rate AMR codec for all GSM phone calls (except for very old phones, which require FR). The transition from EFR/FR to HR AMR severely impacted call quality, but it allowed them to maintain calling capacity while shrinking the footprint of their GSM network.

By 2016, GSM mostly occupied a dedicated 5x5 MHz PCS block, with primarily BCCH channels, and more limited use of hopping TCH channels. This gave T-Mobile enough room to run GSM with minimal spectrum reuse, but reduced the overall spectrum occupied by 2G. Additionally, T-Mobile would enable BCCH channels wherever possible in the PCS band (such as guard bands of its 3G/4G services), which helped conserve spectrum while reducing interference. This was very apparent after the Sprint merger when T-Mobile could use Sprint's guard bands as well.

In 2017, AT&T officially decommissioned its older 2G GSM service, making T-Mobile the only remaining GSM carrier in the United States. This means that older GSM phones now solely relied on T-Mobile for many Americans.

Around 2020, T-Mobile began silently reducing GSM's capacity. Frequency hopping was completely disabled, and most remaining GSM was strictly BCCH, with the exception of limited high-demand areas which still had dedicated, non-hopping TCH channels enabled. This is also when GSM stopped occupying dedicated PCS spectrum. To save space, T-Mobile restricted all remaining GSM to the 3G and 4G guard bands. At this time, T-Mobile was still maintaining adequate spectrum reuse patterns (at least K=3, or 9 BCCH channels), which was tight, but still avoided major interference.

T-Mobile also updated its Network Evolution page in 2021, notifying customers of the upcoming Sprint shutdown in 2022. In addition to the Sprint CDMA/LTE shutdown information, T-Mobile also included a statement that they would be retiring their own 2G and 3G networks in the future. However, there was no expected shutdown date at this time.

In addition, T-Mobile also introduced a policy in mid 2021 which mandated that all customers use a VoLTE capable phone. This was a major change, which impacted many old phones! After this policy was introduced, older devices that relied on 2G and 3G for calls would be blocked from activation on the T-Mobile network based on their IMEI number. This impacted anything from old Nokias, to late 2000s feature phones, to early 2010s Android devices without VoLTE support! This was the first instance of T-Mobile actively forcing people onto 4G LTE.

In 2022, as T-Mobile retired its 3G network, along with Sprint's LTE/CDMA networks, it also silently reduced its own GSM capacity yet again. Following sunset of these networks and the refarming of PCS, GSM was now restricted to the guard bands of LTE B2. In most of the United States, T-Mobile now utilized two, 3-channel (600khz) groups of GSM frequencies, which were placed adjacent to wideband LTE B2 carriers. This configuration allowed GSM to effectively occupy zero dedicated spectrum, which is what allowed it to exist as recently as 2026! Unfortunately, this bare-minimum configuration also introduced issues such as interference between towers. By using only 6 ARFCNs, T-Mobile was now running slightly below bare-minimum capacity for GSM.

As a side effect of this heavy reduction, there was also a common configuration error that affected some areas. Some towers were still broadcasting old neighbor cells! In a GSM network, each tower broadcasts a list of neighbor cells and their frequencies, which allows the MS to initiate seamless handover. In most cases, neighbors that are offline are not problematic because the MS tests the frequency for signal before initiating handover. However, these bad neighbor cells coorespond to modern LTE/5G frequencies, which the MS interprits as a valid neighbor. As a result, handover effectively breaks because the phone and tower are both agreeing to move calls to a nonexistant frequency.

Following the 3G shutdown, T-Mobile also introduced an expected shutdown date for its 2G GSM network: April 2nd, 2024. However, this date ended up being an empty threat since no coverage changes occurred, and the date was later removed from their Network Evolution page.

As the final 3G networks were decommissioned in 2023, T-Mobile's GSM service became the last circuit-switched network in the United States! Any phone incapable of, or not properly configured for VoLTE or VoNR service could now only fall back to T-Mobile. This was especially apparent for roaming customers, since IMS configurations in other countries may not work for American LTE networks. T-Mobile GSM was the final lifeline for older devices, and it was on its way out!

In August 2024, T-Mobile updated its Network Evolution page once again, stating that "Capacity and coverage of T-Mobile's 2G (GSM) network is expected to change starting as early as September 1, 2024." Unlike previous warnings, this time T-Mobile actually did follow through. After September 2024, GSM experienced a nationwide power reduction, reducing the coverage of each 2G cell site over the course of the following months. Additionally, the first permanent GSM coverage reductions were observed in specific markets, such as New York, and parts of Arizona and South Carolina.

Around this time, T-Mobile also shut down the last of its physical regional switches for handling calls over GSM. As the network's MSC became entirely cloud-based and virtual, calls were now routed entirely over the internet. One notable observation is that intercept messages now originated from random states, rather than a static, regional switching center. For example, customers in Illinois could receive intercepts from random states, like MO, NY, or KY, instead of always being from IL.

Following the initial reductions, a new announcement was made in early 2025: T-Mobile's GSM network would experience major coverage and capacity changes starting February 9th, 2025. This date marked the start of T-Mobile's active, slow shutdown of the 2G GSM network.

After 2/9/2025, T-Mobile completely halted maintanence and expansion of its GSM network. New tower builds no longer included GSM, and existing sites were no longer actively maintained, leaving the network in a state of decay. Over the course of the following year, GSM's coverage was heavily reduced on a market-by-market basis. Entire LACs, markets, and even states began losing 2G GSM coverage. At this point GSM was on life support, and coverage loss was unpredictable. The end was near, but we did not know when our areas would be affected.

As of June 2026, T-Mobile published its final annoucement: "As of August 3, 2026, T-Mobile's 2G GSM network will be retired." According to T-Mobile engineers, the shutdown was planned for 8/3/2026 at 6:00 AM in each time zone.

After much anticipation, August 3rd was here. Phone collectors, cellular entuisiasts, and random nerds alike came together to capture the final moments of GSM service in the United States. As the clock struck 06:00 in each time zone, the GSM shutdown was finalized for much of the United States within a matter of hours.

So this is the end, right? ...Not exactly.

While 8/3/2026 marked the official shutdown, select areas actually maintained GSM service a little while longer! Monitors in Boise ID, Reno NV, and Sacramento CA observed shutdowns the following day, on August 4th. The official end of T-Mobile 2G GSM was on August 11th, 2026, in Spokane, WA. Spokane was the final remaining GSM coverage zone, presumably due to the wildfires present at the time.