Samsung promised it for September, and for a while it looked as though the promise might be broken. Now One UI 9 is finally reaching Galaxy S26 Ultra owners in the United States, though only some of them.
Android Central reported on September 23 that the update had begun landing on T-Mobile models of the S26 Ultra. A Reddit user first posted about it, and several others in the thread confirmed they had it too. Other S26 variants on T-Mobile, unlocked phones and handsets on AT&T and Verizon had not received it at that point. T-Mobile may simply have jumped the gun ahead of the wider US release.
What the update brings
The build is based on Android 17 and weighs in at around 4GB. It carries the September security patch and the build number S948USQU4BZID/S948UOYN4BZID/S948USQU4BZID. One UI 9 debuted with the Galaxy Z Fold 8 series.
A rocky run-up
Earlier in the month Samsung had said One UI 9 would start rolling out to the Galaxy S26 lineup in September. Reports pointed to around September 21, and that date passed with nothing. Rumors then suggested Samsung might have delayed the S26 rollout indefinitely. The T-Mobile release looks like a U-turn.
T-Mobile S26 Ultra owners who have not had a notification can go into Settings and check for the update manually. There is no word yet on when unlocked devices or other carrier versions will get One UI 9.
