Samsung has begun rolling out One UI 9 to Galaxy S26 Ultra owners on T‑Mobile in the U.S., according to Reddit users who reported receiving the update.
The update, built on Android 17, is roughly 4 GB in size, carries build numbers S948USQU4BZID / S948UOYN4BZID, and includes the September security patch.
The rollout appears limited to T‑Mobile variants of the S26 Ultra; other S26 models on T‑Mobile, as well as unlocked devices and phones on AT&T and Verizon, have not yet received the software.
Samsung announced earlier this month that One UI 9, which debuted with the Galaxy Z Fold 8, would start reaching the S26 lineup this month. Initial reports had expected the rollout around September 21, but that date passed without a launch, leading to speculation of an indefinite delay.
The current deployment suggests Samsung has reversed the delay, beginning with T‑Mobile Ultra units. Users are advised to check for the update manually in Settings if they have not received an automatic notification.
No official timetable has been provided for when unlocked or other carrier variants will receive One UI 9, but the appearance on T‑Mobile models indicates the broader U.S. rollout may follow soon.