Is Marshmallow update available for Galaxy S5 SM-G900A?

[AC Question]

I have continuoisly looked through several sites...using Drip (the app) to find information about my device. Now I just want answers. I have a Galaxy S5 that we purchased about 6 months ago (bought the phone at Sam's Club) but am with the carrier AT&T it is a SM-G900A. I have heard very little about this device, and would like to know if this device is even receiving the marshmallow update, but if so when would I get it?...so if anyone has any information please do let me know...