If you’re the owner of an AT&T LG G4, you’re in luck. Hot on the heels of T-Mobile rolling the Android 6.0 Marshmallow update to its G4, AT&T is now doing the same. The changelog simply states that the upgrade will bring you to Android 6.0 and add video calling, though the changes in Marshmallow alone are worthy of the upgrade.
The update is to build number MRA58K and will eat 971MB of data, but it seems AT&T requires WiFi to download it anyway. It won’t roll out to everyone at once, so if you don’t get it immediately, be patient and check back every once in a while for your fair share of the Marshmallow goodness.