A166USQSADZI2 – Galaxy A16 5G firmware
Build A166USQSADZI2 is a security update for the Galaxy A16 5G (SM-A166U)
on Android 16 (One UI 8). It first appeared on Samsung's servers on Sep 29, 2026 (method) and has reached
9 regions so far. It raises the bootloader bit from 9 to 10: once installed, the device no longer accepts firmware with bit 9 or lower, so a downgrade to A166USQS9DZH1 is blocked. Samsung still serves this file.
- Model
- SM-A166U
- Android
- Android 16
- Type
- Security
- Bootloader bit
- 10
- First released
- Sep 29, 2026
- Regions
- 9
Rollout timeline by region
The date each region code (CSC) first received A166USQSADZI2, counted from the first release.
| CSC | Region | Released | Rollout | Version (PDA/CSC/MODEM) |
|---|---|---|---|---|
ATT | USA (AT&T) | Sep 29, 2026 | day 0 | A166USQSADZI2/A166UOYNADZI2/A166USQSADZI2 |
DSA | USA | Sep 30, 2026 | +1 day | A166USQSADZI2/A166UOYNADZI2/A166USQSADZI2 |
DSH | USA | Sep 30, 2026 | +1 day | A166USQSADZI2/A166UOYNADZI2/A166USQSADZI2 |
AIO | USA (Cricket) | Sep 30, 2026 | +1 day | A166USQSADZI2/A166UOYNADZI2/A166USQSADZI2 |
CCT | USA (Comcast) | Sep 30, 2026 | +1 day | A166USQSADZI2/A166UOYNADZI2/A166USQSADZI2 |
VZW | USA (Verizon) | Sep 30, 2026 | +1 day | A166USQSADZI2/A166UOYNADZI2/A166USQSADZI2 |
TMB | USA (T-Mobile) | Oct 1, 2026 | +2 days | A166USQSADZI2/A166UOYNADZI2/A166USQSADZI2 |
TMK | USA (MetroPCS) | Oct 1, 2026 | +2 days | A166USQSADZI2/A166UOYNADZI2/A166USQSADZI2 |
USC | USA (US Cellular) | Oct 1, 2026 | +2 days | A166USQSADZI2/A166UOYNADZI2/A166USQSADZI2 |
Download and release notes
samloader download -m SM-A166U -r ATT -v A166USQSADZI2/A166UOYNADZI2/A166USQSADZI2Samsung's release notes and security patch level for this update: SM-A166U / ATT on doc.samsungmobile.com. What each part of the build number means: decode A166USQSADZI2.