Q: I was promoted to a GS-14 position in September of 2012. I plan to retire in September 2015. Will my “High 3” be calculated from September 2015 – September 2015 or from calendar year January 2012 – January 2015?
A: “The ‘high-3 average pay’ is the largest annual rate resulting from averaging an employee’s rates of basic pay in effect over any period of 3 consecutive years of creditable civilian service, with each rate weighted by the length of time it was in effect.” The preceding sentence is OPM’s definition on high three.
If you retire on September 30, 2015, your high three would begin on October 1, 2012. This assumes that, like most retirees, your high three is your last three.