The Microsoft Dynamics GP Year-End Release 2015: US Payroll is out now and available for Download.
Microsoft Dynamics GP Year-End Release 2015: US Payroll – Microsoft Dynamics GP Community
Payroll & HRYear-End & 1099Microsoft & the GP Ecosystem
Archived post from 2015. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.