The latest software for the LG G4 T-Mobile is Android 6.0 Marshmallow , software version H81120x.
To check what version of software is installed on your device:
-  From the Home screen, tap Apps > Settings > General tab > About phone 
-  Tap Software info. 
-  View the current software under Software version. 
Select software for more info:
-  
       Android 6.0 Marshmallow, software version H81120x - Release date December, 2017- Wi-Fi Calling Fix
- KRACK
 
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       Android 6.0 Marshmallow, software version H81120v - Release date May, 2017- Android Security Update (2017-04-01)
- E911 timer fix
 
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       Android 6.0 Marshmallow, software version H81120r - Release date January, 2017- Android Security Update (2017-01-01)
 
-  
       Android 6.0 Marshmallow, software version H81120q - Release date December, 2016- Android Security Update (2016-11-01)
 
-  
       Android 6.0 Marshmallow, software version H81120p - Release date October, 2016- Google security patches
- General maintenance
 
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       Android 6.0 Marshmallow, software version H81120o - Release date July, 2016- Google security patches
- General maintenance
 
-  
       Android 6.0 Marshmallow, software version H81120i - Release date February, 2016- Android 6.0 Marshmallow Software Update
- T-Mobile Video Calling Support added
- General maintenance
 
-  
       Android 5.1 Lollipop, software version H81110n - Release date August, 2015- Security updates (including Stagefright)
- General maintenance
 
-  
       Android 5.1 Lollipop, software version H81110h - Release date June, 2015- Anti-Rollback added
- General maintenance
 
Software Update
-  When the software update is available, the update icon will display in the status bar at the top of the screen. Swipe down from the top and tap the notification. 
-  Tap RESTART & INSTALL. 
Note: If prompted, connect to a Wi-Fi network to download the software update.
-  Your device will restart to perform the update. 
-  When the update is complete, your phone will restart and transition through a series of alerts stating Android is upgrading. 
Troubleshooting
If your devices has not updated, you can manually check if a new software update is available.
-  From the Home screen, tap Apps > Settings > General tab > System updates 
-  Tap Check for new system update to manually check for a new update. 
-  You will be prompted if a new software update is available, tap Download now. Continue from Software Update, step 1. 
To download LG Bridge select your operating system:
-  Connect your mobile device to your computer with a USB cable. 
-  On your mobile device, tap the USB notification in the notification panel. 
-  Tap Media device (MTP) if not already selected. Media device (MTP) must be selected before LG Bridge opens. 
-  Open LG Bridge, then from the Software update tab click Software update button to check for an available update. 
-  If a software update is available, select Start to update your mobile device. 
 
					
				
 
												 
				 
			 
						 
					 
						 
					 
						