At this point in time, the last remnants of Android M (also known as Version 6.0 or Marshmallow) are starting to roll out on the newer versions of Android devices. It began to start coming to Samsung devices at the beginning of this year, and here is the latest news for Android M Version 6.0 Marshmallow and Android N Release Date for Samsung Galaxy S6, S6 Edge, S6 Edge +, Note 5, Note 4, and S5 on Verizon, T-Mobile, AT&T, US Cellular, and Sprint.
So far, Gotta Be Mobile has reported that Android 6.0.1 is on most Galaxy devices. The latest flagship Samsung Galaxy S7 and Galaxy S7 Edge have it out of the box, and it has pretty much rolled out for the Galaxy S6, Galaxy S6 Edge, and the Galaxy S6 Edge Plus. This goes for all five U.S. Carriers.
As for the flagship from two years ago with the Samsung Galaxy S5, it has shown up on Sprint, T-Mobile, and Verizon. There are even reports that Android 6.0 is showing up on Samsung Galaxy S5 Exynos variants, according to Game N Guide.
As for Samsung's phablet family, there are reports that those subscribers from Verizon, Sprint, U.S. Cellular, and T-Mobile have it on the Note 5, with AT&T running a beta update and will apparently start rolling out soon. This also goes for the Galaxy Note 4 and the Note Edge, which has received their upgrade for Sprint, US Cellular, Verizon, but there is a delay for those with T-Mobile.
There are smartphones older than that which will not receive the upgrade, but it will come to certain devices such as the Galaxy A7, Galaxy A8, Galaxy A9, Galaxy J3, Galaxy Alpha, and Galaxy Tab S2. If you own a "newer" Samsung devices are encouraged to check your "Settings" and "System Updates" to see if Marshmallow is ready to download. 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.
When it comes to Android N, it was no surprise when it was announced at the Google I/O Developer Conference, but it is surprising that it the new operating system is now available as a public beta version. PC Advisor states that Android N could be available in September and come straight to 2016 Nexus phones, and that is pretty quick.
As for when it will comes to Samsung, there is much speculated that Android N will officially roll out onto Samsung devices at the first quarter of 2017. This is just following the pattern of the release of Android M.