FERS supplement calculation


Q. My human resources staff calculated my estimated Social Security FERS supplement, and it is considerably lower than my Social Security calculation (calculated to initiate at age 62). I am retiring at 56 with 34 years.  The HR staff has stated that they do not have the formula but only enter the numbers in a program estimator.  The FERS handbook says the FERS Social Security supplement approximates the Social Security annuity. The FERS Social Security supplement doesn’t seem like a very close approximation. The FERS Social Security supplement calculates out at approximately $11,000, and the Social Security annuity is approximately $17,000. If I delay initiating SS past the age of 62, does the FERS SS supplement continue during that time, or does it only apply between 56 and 62?

A. The actual method used to calculate your special retirement supplement is described in Chapter 51 of the Office of Personnel Management’s CSRS and FERS Handbook for Personnel and Payroll Offices. You can see how that’s done by going to www.opm.gov/retire/pubs/handbook/C051.pdf. However, you’ll soon realize that employees don’t have the information needed to get an answer. For that reason, OPM has a simple formula that will allow you to estimate what your SRS will be.  Here it is:

Take the latest estimate of your Social Security benefit at age 62 provided by the Social Security Administration, multiply it by your years of FERS service rounded up to the next higher year, and divide the product by 40.

Because the Social Security estimate is based on the assumption that you will be working to age 62, there is bound to be a difference between that and what you’d receive at age 56. Also, you need to be aware that the Social Security estimate will include all Social Security-covered service, while your benefit will be based solely on your FERS-covered service.


About Author

Reg Jones was head of retirement and insurance policy at the Office of Personnel Management. Email your retirement-related questions to fedexperts@federaltimes.com.


  1. If I retire at 57 with 31 yrs of service and receive the special supplement until 62 yo, when my social security is recalculated will i receive less money than me original estimate if i do not work again? What is the formula?

    • Your special retirement supplement is based solely on the amount of Social Security benefit you earned while a FERS employee. Unless you have other Social Security-covered employment before, during or after your FERS career, the amount you receive at age 62 should be the same.

  2. The estimate we receive at age 56 assumes you will be earning wages at the same rate until age 62, when in fact we will not. The actual amount that we receive at 62 should be less then the estimate.

  3. In June I’m supposed to receive the retirement supplement following my April 56th birthday. I currently receive social security disability checks. Please advise if my disability payments will decrease during the six year supplement period of time. Also, on my 62nd birthday, will my pension and disability payments return to the amount that I’m receiving now since I’m already receiving social security.

    • Did you retire under FERS, receive an annuity and were later approved for SSDI or did you retire on FERS disability and were later approved for SSDI?

        • In that case, you’re entitled to your full annuity and, when you reach your MRA, an unreduced special retirement supplement.

  4. Marcelo Mendez on

    I retired under FERS as a law enforcement receiving FERS Annuity supplement. I worked Until the mandatory retirement at 57 and receiving a pension and the supplement. In reviewing my last statement, it shows a reduction from $1397.00 to $1006.00. If I used the formula, 27 years divided by 40 years Social Security expectancy would be approximately 0.675 and multiply by $2000.00 Social Security would be approximately $1350.00. I believe there is a mistake but wanted to verify with you.

    • Based on what you have written, there is no way to tell what caused the reduction in your annuity. One possibility is that you exceeded the annual Social Security earnings limit and your SRS was reduced or eliminated, Another is that you turned age 62 and the special retirement supplement ended. To find out what actually caused the reduction, you’ll need to check with OPM. Give them a call at 1-888-767-6738.

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