Right now, there is a shift that is happening in the world of Android as an upgrade to Google's operating system is in a state of transition. Most Android devices including our subject of this article, Samsung, already have the current version with Marshmallow (also known as Android M or Android 6.0). However, there will be and upgrade to Nougat (also known as Android 7.0 and Android N). This is what is known about Android M Version 6.0 Marshmallow and Android Nougat Release Date for Samsung Galaxy S6, S6 Edge, S6 Edge +, Note 5, Note 4, Note 3, and S5 on AT&T, Verizon, US Cellular, T-Mobile, and Sprint.
Samsung is practically a champion for Android. The flagship series of the S7 and the S7 Edge comes with Marshmallow coming right out of the box. This is the case with Samsung Galaxy S6, and then Galaxy S6 Edge. As for that the Galaxy S5, it is available on Sprint, T-Mobile, and Verizon, with no flagships no lower than that. So, if you have a Galaxy S4 and S3, good luck.
As for the Samsung phablets, it has come to Verizon, Sprint, T-Mobile, and AT&T for that Samsung Note 5. As for the Note 4, it should be on all of the carriers now. No doubt Marshmallow will be on the Note 7 (it will skip the Note 6 name)right out of the packaging when it comes out soon.
Other news about Samsung includes the Galaxy A5, and you will be pleased to know that the first-generation model has Android 6.0.1. So far, it has began in Europe and South Africa, and it does look like the A3 has it yet, according to Tech Times.
It should be noted that Android Nougat is coming out very soon, and it will come to Nexus devices first, possibly even older models. Gotta Be Mobile suggests that it will come out in Q4 of 2016, but it could be happening early 2017. After years of watching with new releases of Android upgrades, this seems to be the pattern.
If you own a "newer" Samsung devices are encouraged to check your "Settings" and "System Updates" to see if Marshmallow is ready to download OTA. This upgrade might not be ready depending on your U.S. carrier, as it has been shown that certain carriers receive the Android upgrade before others, with no real pattern.