By the time I was 54 I realized that I would be retiring from my current job. I'd been with the department of education for 17 years and had set my goal on 20 years. I put in 24 years, to the day, and retired with a total of 26 years toward my Arizona State retirement by purchasing two of my four years of military service as an add on. This put me over 25 which fit nicely into my retirement.