Samsung Galaxy S21 Ultra (SM-G998U) - TMB - G998USQSEGYA5 firmware
Samsung Galaxy S21 Ultra firmware G998USQSEGYA5 is the Android 14 build for the Samsung Galaxy S21 Ultra (model SM-G998U), released by Samsung for USA (T-Mobile) (TMB). It was built on 22 January 2025, carries the 2025-02-01 Android security patch, has changelist 28579955. The package combines system build G998USQSEGYA5 (AP/PDA) with CSC build G998UOYNEGYA5 for the TMB region code. The download is 7.9 GB and has MD5 checksum 626a61c8b322e3bd40ec8b799ac54c9f, so you can verify the file after downloading. SamMobile added this file to the firmware archive on 24 February 2025.
How to flash G998USQSEGYA5 on the Samsung Galaxy S21 Ultra (SM-G998U)
We recommend updating through Samsung's own tools: over-the-air (Settings › Software update) or Samsung Smart Switch on a PC. Flash the full firmware with Odin only when you are sure about the risks. A wrong region or a failed flash can brick the device, and SamMobile is not responsible for any damage.
- Download the firmware package above and extract the ZIP. It contains the AP (PDA), BL, CP and CSC files, plus a HOME_CSC file.
- Download and extract Odin on a Windows PC, and install the Samsung USB drivers if the PC does not detect the phone.
- Switch the device off and boot it into Download mode (usually Volume Up + Volume Down while connecting the USB cable, or Volume Down + Bixby + Power on older models).
- Open Odin. The ID:COM box turns blue when the device is connected.
- Load the files in their slots: BL, AP, CP and CSC. Use HOME_CSC to keep your apps and data, CSC to wipe the device.
- Leave Re-Partition unticked and click Start. The device reboots when Odin shows PASS. The first boot after a flash can take a few minutes.
Step-by-step PDFs: 5-file firmware and 1-file firmware.
What the build numbers mean
PDA / AP (G998USQSEGYA5) is the Android system build; its last three characters encode the year, month and revision. CSC (G998UOYNEGYA5) is the region and carrier configuration, and CP is the modem firmware. The product code TMB identifies the region or carrier this package was made for (USA (T-Mobile)); our list of Samsung CSC codes maps every code to its country and carrier. Flashing a package for a different product code changes carrier features and can be refused by the bootloader, so pick the one that matches the CSC shown under Settings › About phone › Software information.