End-of-support date of version 1511 of the current branch for System Center Configuration Manager on Dec 8th, 2016, each branch release is supported for 12 months from its general available (GA) release date, the first release date for branch 1511 was Dec 8^th, 2015.

After Dec 8^th, 2016 Configuration Manager with current branch 1511 will no longer provide security fixes.

Note: 1610 branch update is released on Nov 18^th, 2016, it’s important to upgrade site hierarchy before Dec 8^th, 2016.

Abduljalil Abou Alzahab