LG G3 units of major mobile operators in the United States must have been passed out from the official Android 6.0 Marshmallow upgrade. Verizon is the only carrier until now to roll out said update on the device.
All unlocked, Verizon and international units of LG G3 have already been updated to Android 6.0 Marshmallow via official over-the-air (OTA) release, but mobile operators in the U.S. seemed to have been passed out. Sprint, T-Mobile, AT&T and US Cellular versions of the device were unfortunately last seen updated last year.
Sprint
Sprint is considerably leading in the Marshmallow upgrade race. However, the carrier seemed to remain unconscious that there are still G3 owners who wish to upgrade to Android 6.0. G3 units under Sprint that still run on Android 5.0 and were last seen updated in November 20, 2015 with minor updates and bug fixes.
Based on the Marshmallow map, this carrier is hugely focusing on updates for Samsung devices, being able to roll out Android 6.0 on Galaxy S6 edge+, Galaxy S6 edge, Galaxy S6, Galaxy Note and Galaxy Note 4. Outside Samsung, Sprint released the update to LG G4 and G Stylo, Moto X Pure Edition (2015), HTC One A9, One M9 and One M8, and the Google Nexus family.
There is not a clear statement from Sprint as to when it will be releasing Marshmallow to its LG G3 units.
T-Mobile
Being the carrier generous enough to release details of software status on its devices, T-Mobile is also not well on its way to G3. In its Marshmallow track list, G3 is among the five remaining devices to have not been updated to Android 6.0 and is stuck on the magenta carrier's manufacturer development stage.
There are 18 devices in the list, eight were already updated and three are still in the testing stage. As to the exact release date, T-Mobile is not yet clear about it.
AT&T
AT&T is at the tail of Marshmallow race this time. With only around eight devices updated to Marshmallow, the carrier is expected to make up in the coming weeks. As for its G3 units, the device was last seen updated in 2015.
Versions with model number D725 were last updated on April 06, 2015 with Android 5.0.2 Lollipop, while versions with model number D820 were last updated on July 01, 2015 with Android 5.0.1 Lollipop.
There are no official statements when these devices will get Marshmallow.
US Cellular
Finally, US Cellular units of LG G3 remained under the Lollipop bracket with Android 5.0.1. There is no official release date as of now.
