Short answer
“GSM MVNO” used to mean a carrier reselling AT&T or T-Mobile, as opposed to CDMA carriers reselling Verizon or Sprint. That split is over. Every US carrier now runs LTE and 5G, every phone uses a SIM or eSIM, and the only question left is which of three networks a brand resells.
Managed by M. Curtis McCoy · Last reviewed September 20, 2026 · How we make money
What to ask instead
Not “is it GSM?” but: which network does this carrier use, does my phone support that network’s bands, and is VoLTE enabled on it? Get those three right and the phone works. Get the third one wrong and you get data with no phone calls.
When GSM stopped mattering
The GSM-versus-CDMA distinction died with the 2G and 3G networks that carried it. The dates come from the carriers:
| Network | Retired |
|---|---|
| AT&T 3G | 2022 — AT&T’s own customer FAQ gives only the year |
| Sprint 3G (CDMA) | March 31, 2022 |
| Sprint LTE | June 30, 2022 |
| T-Mobile 3G (UMTS) | July 1, 2022 |
| Verizon 3G (CDMA) | January 3, 2023 |
| T-Mobile 2G (GSM) | August 3, 2026 |
That final row retired the last true GSM network in the United States. T-Mobile had kept 2G alive for alarm panels, asset trackers and old flip phones long after everyone else moved on. When it went, GSM went with it.
The three networks everything runs on
There are three host networks left. Every other brand you have heard of is reselling one of them. Below are carriers whose host network is confirmed by the carrier itself or by ownership — not by a comparison site.
T-Mobile network
T-Mobile · Metro by T-Mobile (T-Mobile-owned) · Mint Mobile (T-Mobile acquired parent Ka’ena Corp in 2024) · Google Fi (Google’s own coverage page) · Assurance Wireless (its own help center)
AT&T network
AT&T · Cricket Wireless (AT&T-owned) · H2O Wireless
Verizon network
Verizon · Visible (wholly owned Verizon brand, stated on its own About page) · Total Wireless (Verizon-owned) · Spectrum Mobile (Charter’s own Form 10-K states it uses the Verizon network)
For every other brand, check the directory. Where a carrier will not state its host network, we leave the field blank rather than copy a guess.
Find your carrier in the directory.
How to find out which network you are actually on
- Check the carrier’s own support pages first. Not a comparison site, not a forum. If the carrier says it, it counts.
- Look at your phone’s network settings. On Android, Settings → About phone → SIM status often names the host network in the operator field. On iPhone, Settings → General → About shows the carrier and network provider.
- Read your SIM. Many MVNO SIMs are physically printed or branded by the host network.
- Check your phone’s bands against the network before you switch, especially mid-band 5G. An unlocked phone built for one network can be missing bands another depends on.
- Confirm VoLTE. With 2G and 3G retired, voice calls ride LTE. If your phone is not on the carrier’s VoLTE-approved list, you get data and no calls.
Common questions
Which carriers are GSM in 2026?
None, in the original sense. T-Mobile’s 2G GSM network was the last one and it was retired in August 2026. AT&T and T-Mobile are the networks people mean when they say GSM, but both run LTE and 5G now.
Is an unlocked GSM phone going to work on any carrier?
Not automatically. “Unlocked” means no carrier lock. It says nothing about band support or VoLTE approval, which are what actually decide whether the phone works.
Can I move my SIM to another carrier?
Usually no. The SIM belongs to the carrier, not to you. You keep your number by porting it; the new carrier issues a new SIM or eSIM.
What is the difference between an MVNO and a real carrier now?
Towers. An MVNO owns none and buys wholesale capacity. Coverage is identical to the host network; what usually differs is deprioritization during congestion, hotspot allowances and customer support.
Does GSM vs CDMA affect porting my number?
No. Number portability is an FCC requirement and works across all carriers. What you need is your account number and transfer PIN from the carrier you are leaving.
The question that replaced “GSM or CDMA”
Which network are you on, and where can you take that phone?
Match the phone to the network first. Price second. Doing it the other way around is how people end up with a SIM that gets data and no calls.