One UI 9 Reaches US Samsung Galaxy S26 on T-Mobile First: 4.1GB Update, Verizon and AT&T Still Waiting
Samsung's stable One UI 9 update, built on Android 17, began reaching Samsung Galaxy S26 phones in the United States on Wednesday, September 23, starting with carrier-locked T-Mobile units. The download is about 4.1GB and carries the September 2026 security patch. Unlocked, Verizon and AT&T models had not received it as of Friday, September 25.
- Update: One UI 9.0 with Android 17
- Build: S948USQU4BZID on the T-Mobile Galaxy S26 Ultra; other models show builds ending in BZID
- Size: about 4.1GB (reported as 4,183MB)
- Security patch: September 2026
- US availability: T-Mobile first; unlocked, Verizon and AT&T not yet, with no date announced
- How to get it: Settings > Software update > Download and install
Which US Galaxy S26 phones have One UI 9 right now?
Only T-Mobile's carrier-locked Galaxy S26 models are getting One UI 9 in the US so far. The first owner reports on September 23 came from the T-Mobile Galaxy S26 Ultra, and early coverage said the regular Galaxy S26 and Galaxy S26+ on T-Mobile had not seen it yet. By September 24, reports described the rollout as covering all three T-Mobile models: the Galaxy S26, Galaxy S26+ and Galaxy S26 Ultra.
The only full build number published so far belongs to the Galaxy S26 Ultra (model SM-S948U). If you own a T-Mobile Galaxy S26 or S26+ and nothing shows up yet, Samsung's rollouts arrive in stages, so check again over the next few days.
| US Galaxy S26 version | One UI 9 status (September 25) |
|---|---|
| T-Mobile Galaxy S26 Ultra | Rolling out, build S948USQU4BZID |
| T-Mobile Galaxy S26 and S26+ | Rolling out according to reports, builds ending in BZID |
| Verizon | Not yet, no date announced |
| AT&T | Not yet, no date announced |
| Unlocked (including unlocked phones used on T-Mobile) | Not yet, no date announced |
Samsung has not said why T-Mobile's carrier-locked models went ahead of unlocked phones this time.
Why is the US One UI 9 update 4GB when Korea's was 650MB?
The US Galaxy S26 build is far larger than the one South Korea received. When stable One UI 9 started in Korea on September 16, the Korean Galaxy S26 update weighed about 650MB and used firmware ending in BZI6. The US T-Mobile build ends in BZID and weighs about 4.1GB. Samsung has not explained the gap, but a download this size needs free storage and is best done on Wi-Fi.
Was One UI 9 for the Galaxy S26 delayed in the US?
Yes, by a few days at least. Samsung's Canadian and Thai newsrooms had listed September 21 as the start date for the Galaxy S26 series, as we noted in our report on Samsung's One UI 9 schedule. The update did not appear on US phones that day, and Samsung briefly acknowledged a delay in some regions without giving a reason. Some reports had pointed to early October before T-Mobile's rollout began.
What One UI 9 adds to the Galaxy S26
One UI 9 on the Galaxy S26 is close to the software that shipped on the Galaxy Z Fold8 this summer. The main additions:
- My FanCam: records wide footage, then lets you pick a subject for AI tracking and reframing.
- Now Brief: cards you can generate with AI.
- Now Nudge: a simpler layout for its suggestions.
- Galaxy AI tools: updates to Creative Studio, Interpreter, Document Scan and Voice Recorder.
- Warranty and Care: a new menu in Settings.
How to install One UI 9 on a US Galaxy S26
- Back up your phone with Samsung Cloud or Smart Switch before a major Android version jump.
- Connect to Wi-Fi and make sure you have well over 4GB of free storage.
- Open Settings > Software update > Download and install.
- If One UI 9 is offered, follow the prompts to download and install it. If not, the rollout has not reached your model or carrier yet.
For full hardware details, see our Samsung Galaxy S26 Ultra spec page. Samsung's schedule in Thailand puts the Galaxy S25, Z Fold7 and Z Flip7 next, from September 28, but Samsung has not given a US date for those phones yet.
Frequently Asked Questions
Is One UI 9 available for the Galaxy S26 in the US?
Yes, but only on T-Mobile so far. Samsung began rolling out stable One UI 9 with Android 17 to carrier-locked T-Mobile Galaxy S26 phones on September 23, 2026. Unlocked, Verizon and AT&T Galaxy S26 models had not received it as of September 25.
When will Verizon and AT&T Galaxy S26 phones get One UI 9?
Samsung, Verizon and AT&T have not announced a date. A first carrier rollout is usually a sign that other versions will follow, but nothing is confirmed, so Verizon and AT&T Galaxy S26 owners should check Settings > Software update regularly.
When will the unlocked Galaxy S26 get One UI 9 in the US?
There is no date yet. Unlocked US Galaxy S26 phones, including unlocked units used on T-Mobile's network, had not received One UI 9 as of September 25, 2026, even though T-Mobile's carrier-locked models were already updating.
How big is the One UI 9 update for the US Galaxy S26?
The US T-Mobile One UI 9 update for the Galaxy S26 is about 4.1GB, reported as 4,183MB. It includes Android 17 and the September 2026 security patch. The Galaxy S26 Ultra build number is S948USQU4BZID.
How do I check for One UI 9 on my Galaxy S26?
Open Settings, tap Software update, then Download and install. If One UI 9 has reached your model and carrier, the roughly 4.1GB download will be offered. Use Wi-Fi and back up your phone first.
