It's been a while since I had to delve into the Current Branch/Current Branch for Business/Long Term Servicing Branch servicing matrix Microsoft created for Windows 10.
As of April 8, I can avoid it no longer, as Microsoft has designated its November 2015 update of Windows 10 as its new Current Branch for Business (CBB) release. (Before today, the latest Windows 10 release considered a CBB was Windows 10 1507, a k a the July 2015 RTM version of Windows 10 released last summer.)
Microsoft will be publishing updated media for Windows 10 1511 -- the version also known as Windows 10 1511 and Build 10586 -- "in the coming weeks" through Windows Update, Windows Update for Business, Windows Server Update Services, its Volume Licensing Service Center and MSDN.
What's technically considered the latest CBB release is Windows 10 1511 plus a March cumulative update (KB3140768).