FERS Part-Time Service

calculating your prorated annuityFrequently federal employees will work periods of part-time service, especially early on in their careers. If an employee paid into FERS during this part-time service, he will get credit for that time, both for his annuity and for retirement eligibility. Although part-time service can count as FERS service for retirement, it is not credited the same way full-time employment is. Employees who have worked FERS part-time service at any point in their careers will have their federal annuity prorated to reflect this fact. The reduction in federal annuity is directly proportional to these reduced hours.

Calculating your prorated annuity

When calculating your prorated annuity, start by using the same retirement formula as all other FERS employees. Then, to calculate your prorated factor, divide the total hours you actually worked as a FERS employee over your entire career by the number of hours you would have worked if all of your service were full time. Lastly, you can multiply your federal annuity by the prorated factor to find the amount that you will actually receive. Per OPM, one year of full-time work equals 2,087 hours.

pro rated formula
For example, suppose you worked as a FERS employee for thirty years, but for some of those years you worked FERS part-time service. Over the course of your career, you accrued only 54,220 hours. Had you worked full time, you would have accrued 62,610 hours in that time (using the OPM assumption that a full-time year equals 2,087 hours). To find your prorated factor, you would divide 54,220 by 62,610, giving you .87, or 87%. If your standard annuity was $3,000 per month, your monthly prorated annuity in this scenario would be $2,610.

monthly prorated annuity
If you have FERS part-time service, be sure to take into account how this will affect your annuity calculation. Part-time service is treated differently than non-deduction service, military service, and breaks in service. For more on these topics, please see our service-history video. It is vital to understand your service history and make sure you are getting credit for the appropriate time. Finding out your annuity is less than you thought due to a misunderstanding of your service history, is not the kind of surprise anyone wants to experience.