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Your basic annuity is computed based on your length of service and “high-3” average salary. You also receive credit for unused sick leave if you retire on an immediate annuity. To determine your length of service for computation, add all your periods of creditable service, and the period represented by your unused sick leave, then eliminate any fractional part of a month from the total.

High-3 Average Salary

Your “high-3” average pay is the highest average basic pay you earned during any 3 consecutive years of service. These three years are usually your final three years of service, but can be an earlier period, if your basic pay was higher during that period. Your basic pay is the basic salary you earn for your position. It includes increases to your salary for which retirement deductions are withheld, such as shift rates. It does not include payments for overtime, bonuses, etc.


Here is how the CSRS annuity formula is calculated:

CSRS Annuity Formula
Years of Service
What You Receive
First 5 years of service 1.5 percent of your high-3 average salary for each year
Second 5 years of service Plus

1.75 percent of your high-3 average salary for each year

For all years of service over 10 Plus

2 percent of your high-3 average salary for each year.

Reductions in Annuity

Your annuity will be reduced if:

  • You retire before age 55 (unless you retire for disability or under the special provisions for law enforcement officers, air traffic controllers, and firefighters); your annual annuity will be reduced by one-sixth of 1 percent for each full month you are under age 55.
  • You didn’t make a deposit for service performed prior to October 1, 1982, during which no deductions were taken from your pay (non-deduction service after that date is not used in the computation of benefits if the deposit is not paid); your annual annuity will be reduced by 10% of the deposit due, including interest.
  • You didn’t make a redeposit of a refund for a period of service that ended before March 1, 1991, or if you retired prior to October 28, 2009, service that ended prior to October 1, 1990; your monthly annuity will be actuarially reduced based on the amount of redeposit due, including interest, divided by a factor for your age at retirement. 
  • You provide for a survivor annuity:
    • To provide a full survivor benefit for your current or former spouse, your annual annuity will be reduced by 2.5 percent of the first $3,600, plus 10 percent of the annuity over $3,600.
    • To provide a survivor annuity for a person who has an “insurable interest” in you, your annual annuity would be reduced from 10 to 40 percent, depending on the difference in your age and the age of the person named.

Cost of Living Adjustments

Your annuity will be increased periodically by cost-of-living increases that occur after you retire. Your initial cost-of-living increase will be prorated based on how long you have been retired when that cost-of-living increase is granted.

Maximum Payable

The maximum benefit you can receive from CSRS is 80 percent of your high-3 average salary, plus credit for your sick leave. This limit generally affects only those who have more than 41 years 11 months of service when they retire.

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Special Computation for Law Enforcement Officers, Firefighters and Nuclear Materials Couriers

CSRS Annuity Formula
If retired under the special provision for firefighters, law enforcement officers, or nuclear material couriers, Supreme Court Police or Capitol Police
Years of Service
What You Receive
First 20 years of CSRS law enforcement officer, firefighter and/or nuclear material courier service 2.5% of your high-3 average salary for each year
All remaining CSRS service Plus

2% of your high-3 average salary for each year

Disability Retirement Computation

If you retire for disability, you may be guaranteed a minimum annuity equal to the smaller of:

  • 40 percent of your “high-3 average salary”, or
  • the regular annuity obtained after increasing your service by the time between the date of your retirement and your 60th birthday.

The guaranteed minimum applies if you are under age 60 when you retire and your earned annuity based on your actual service is less than this minimum.


The guaranteed minimum does not apply if you are receiving military retired pay and/or compensation from the Veterans Administration in lieu of all or part of the military retired pay. However, if your earned annuity plus your military benefit (or compensation) is less than what it would have been under the guaranteed minimum, the annuity is increased to bring it up to that level.


Disability annuities for individuals who performed service in an enhanced position such as law enforcement officer, firefighter, nuclear materials courier, Capitol Police, or Supreme Court Policy will be credited at the higher 2.5% for that service.

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