Samsung Galaxy S21 Ultra 5G (SM-G998U) Firmware Overview
What is the latest SM-G998U firmware?
G998USQSJHZB1, released March 23, 2026 with Android 15. It is a security update on bootloader binary 19. The archive holds 27 official builds across 7 regions (CSC). Each one is the full stock ROM (flash file) for Odin, not an OTA patch.
Is the Samsung Galaxy S21 Ultra 5G still getting updates?
The last build arrived in March 2026. Updates have slowed down — models late in their support period move to quarterly or half-yearly security patches before they stop.
Can I downgrade the SM-G998U firmware?
Only to builds with the same bootloader binary (the Bit column) or higher. In the archive the binary of this model rose from 17 to 19:
- Binary 19 — since Jan 2026
- Binary 18 — since Dec 2025
- Binary 17 — since Sep 2025
A phone already on binary 19 rejects builds with a lower binary in Odin ("SW REV CHECK FAIL"), so it can go back to an earlier Android version only if that version has a binary 19 build. How to read a build number.
All SM-G998U firmware builds
| Build / PDA | Bit | Region (CSC) | Android | Date | Download Link |
|---|---|---|---|---|---|
|
G998USQSJHZB1
Security update
|
19 | VZW | 15 |
2026-03-23 | Download |
|
G998USQSJHZB1
Security update
|
19 | SPR | 15 |
2026-03-19 | Download |
|
G998USQSJHZB1
Security update
|
19 | TMB | 15 |
2026-03-19 | Download |
|
G998USQSJHZB1
Security update
|
19 | CCT | 15 |
2026-03-19 | Download |
|
G998USQSJHZB1
Security update
|
19 | CHA | 15 |
2026-03-19 | Download |
|
G998USQSJHZB1
Security update
|
19 | ATT | 15 |
2026-03-18 | Download |
|
G998USQSJHZB1
Security update
|
19 | USC | 15 |
2026-03-18 | Download |
|
G998USQSJHZAA
Security update
|
19 | VZW | 15 |
2026-02-02 | Download |
|
G998USQSJHZAA
Security update
|
19 | ATT | 15 |
2026-02-02 | Download |
|
G998USQSJHZAA
Security update
|
19 | CCT | 15 |
2026-01-29 | Download |
|
G998USQSJHZAA
Security update
|
19 | CHA | 15 |
2026-01-29 | Download |
|
G998USQSJHZAA
Security update
|
19 | TMB | 15 |
2026-01-28 | Download |
|
G998USQSJHZAA
Security update
|
19 | SPR | 15 |
2026-01-28 | Download |
|
G998USQSJHZAA
Security update
|
19 | USC | 15 |
2026-01-28 | Download |
|
G998USQSIHYL1
Security update
|
18 | VZW | 15 |
2025-12-22 | Download |
|
G998USQSIHYL1
Security update
|
18 | CHA | 15 |
2025-12-19 | Download |
|
G998USQSIHYL1
Security update
|
18 | CCT | 15 |
2025-12-19 | Download |
|
G998USQSIHYL1
Security update
|
18 | ATT | 15 |
2025-12-18 | Download |
|
G998USQSIHYL1
Security update
|
18 | USC | 15 |
2025-12-17 | Download |
|
G998USQSIHYL1
Security update
|
18 | SPR | 15 |
2025-12-17 | Download |
|
G998USQSIHYL1
Security update
|
18 | TMB | 15 |
2025-12-17 | Download |
|
G998USQSHHYI1
Security update
|
17 | VZW | 15 |
2025-09-30 | Download |
|
G998USQSHHYI1
Security update
|
17 | CHA | 15 |
2025-09-26 | Download |
|
G998USQSHHYI1
Security update
|
17 | CCT | 15 |
2025-09-26 | Download |
|
G998USQSHHYI1
Security update
|
17 | SPR | 15 |
2025-09-25 | Download |
|
G998USQSHHYI1
Security update
|
17 | TMB | 15 |
2025-09-25 | Download |
|
G998USQSHHYI1
Security update
|
17 | ATT | 15 |
2025-09-25 | Download |
Latest SM-G998U Firmware by Region
The newest build for each region (CSC) code. Not sure which region your phone uses? See the CSC code guide.
| Region | Latest build | Bit | Android | Date |
|---|---|---|---|---|
| ATT | G998USQSJHZB1 | 19 | 15 | 2026-03-18 |
| CCT | G998USQSJHZB1 | 19 | 15 | 2026-03-19 |
| CHA | G998USQSJHZB1 | 19 | 15 | 2026-03-19 |
| SPR | G998USQSJHZB1 | 19 | 15 | 2026-03-19 |
| TMB | G998USQSJHZB1 | 19 | 15 | 2026-03-19 |
| USC | G998USQSJHZB1 | 19 | 15 | 2026-03-18 |
| VZW | G998USQSJHZB1 | 19 | 15 | 2026-03-23 |
How to Flash SM-G998U Firmware
Put the Samsung Galaxy S21 Ultra 5G into Download Mode, load the BL, AP, CP and CSC files into Odin on a Windows PC and press Start. Pick a build with Bit 19 or higher if your phone is already on the latest firmware. Use HOME_CSC to keep your data, CSC for a full wipe.