Samsung seems to love them some beta tests. After completing a round of Android 6.0 Marshmallow betas in South Korea and the UK for the Samsung Galaxy S6 and S66 Edge, the company is now heading State-side and doing the same for those with AT&T’s Samsung Galaxy Note 5.
It sounds like this test is on a much smaller scale than the other phones and regions, with only about 200 people being included in this initial round. It’s not yet known if AT&T and Samsung will open the test up to more users over time.
Those lucky enough to be selected should have received an email with instructions on participating, after which they’re prompted to download a 1.4GB update that comes in as build MMB29K.N920AUCU2BPB1. It also seems very recent, with the build showing February 1st as the Android security patch level. Be sure to check your email to see if you were picked. Otherwise, sit tight and it might not be long before this rollout reaches the bulk of the userbase.