
Samsung Galaxy Mega 6.3 LTE (Metro PCS)
The latest firmware for Samsung Galaxy Mega 6.3 LTE (Metro PCS) (SGH-M819N) is M819NUVUBOH3 with Android 4.4.4 (KitKat), released on August 23, 2015 for 1 region (CSC). Every official firmware build for SGH-M819N, newest first: one row per build with all regions (CSC) that received it.
Each firmware build has its own page at https://samfirm.shop/build/{PDA}, where {PDA} is the build number from the list above. Example: https://samfirm.shop/build/M819NUVUBOH3
All 4 builds in our database run Android 4.4.4 (KitKat). The newest build, M819NUVUBOH3, was released on August 23, 2015. No new build has appeared for 136 months, so regular updates for this model have most likely ended.

SGH-I927

SGH-S730M

SGH-T999N

SGH-T989D

SGH-T859

SGH-T599V

SGH-I757M

SGH-I747
The newest firmware for SGH-M819N runs Android 4.4.4 (KitKat): build M819NUVUBOH3, released on August 23, 2015.
The latest build for SGH-M819N, M819NUVUBOH3, was released on August 23, 2015 (11 years ago).
SGH-M819N has had no new firmware for 136 months, so regular updates have most likely ended.
Yes, all firmware files for SGH-M819N are 100% official, original, and obtained directly from Samsung servers.
To flash SGH-M819N, you need to download the appropriate firmware, put your device into Download Mode, and use the Odin tool to load the BL, AP, CP, and CSC files.
Downgrading is only possible if the bootloader version (binary bit) of the old firmware matches the current one. Always check the binary version before flashing SGH-M819N.