The Lollipop update is being rolled out to AT&T’s LG G3. This is following the release of new software for the G3 models from other parts of the world that started last year.
If you own a G3 from AT&T you will receive a notification for an update pretty soon, just do the usual and download and install it.
This new update is around 690MB and you will probably be waiting around 5 minutes for the update to end and you will be left with a 5.0.1 running G3.
Just in case you didn’t receive the notification yet, don’t be worried you can always force the smartphone to check for updates and then the notification will appear.