The basic annuity as an CSRS employee eligible to retire under the special

provisions for law enforcement officers and firefighters is computed as follows:

• 50% of high-3 average salary

• Plus 2% percent of your high-3 average x by # of years and whole months

  of service exceeding 20

• plus unused sick leave

Premium pay you receive as a firefighter or law enforcement officer under

section 5545(c), or availability pay under section 5545(a), of title 5, United

States Code, is included in your high-3 average salary. Your high-3 is then used

in the 2-part formula above.

Unlike most other federal employees, there is no reduction in the basic

annuity for retirement under age 55. However, the basic annuity amount may

be reduced to provide survivor benefits, or if there is service for which

you received a refund or that was not covered by retirement deductions.

Example:
Age	47
High-3	$70,000
Years of Service	25
.50 x $70,000	= $35,000
.02 x $70,000 x 5	= $  7,000
	$42,000

If you are a CSRS Offset employee, Civil Service Retirement and Social Security cover you at the same time. You will receive a full CSRS annuity special computation, if you qualify under special provisions as a law enforcement officer or firefighter.  However, the CSRS Offset annuity will be reduced if you become eligible to receive Social Security benefits, usually at age 62. See CSRS Offset Basic Annuity Calculation for details. 

Source:  OPM RI 83-14