CSRS / FERS Federal Retirement Planning Tools and Resources: Thrift Savings - TSP, FEGLI, FEHB and more.
Home     Articles     News     Resources     Find A Professional     Retirement Seminars     FREE NEWSLETTER    
 Financial Professionals Directory

Find a financial professional in your area. Click here

 Retirement Seminars

Federal retirement seminars for agencies.
Learn more

 Top 5 Resources

1. TSP Roth option
2. GS pay scale 2015
3. Best dates to retire
4. Latest TSP returns
5. Discount dental plans

 CSRS Retirement
 Overview - CSRS
 Eligibility - CSRS
 Creditable Service -CSRS
 Survivor Benefits - CSRS
 Annuity Calculation-CSRS
 FERS Retirement
 Overview - FERS
 Eligibility - FERS
 Creditable Service -FERS
 Survivor Benefits - FERS
 Thrift Savings Plan
 Thrift Savings -Overview
 TSP Investment Choices
 TSP Loan Program
 TSP Contributions
 TSP Roth Option
 TSP Withdrawals
 TSP Returns
 TSP.gov Account Access
 TSP Forms Library
 TSP Talk Online Forum
 FEGLI - Life Insurance
 FEHB - Health Benefits
 FEDVIP - Dental/Vision
 FLTCIP - Long-Term Care
 FSAFEDS - Flex Spending
 Financial Planning
 Tax Tips
 Find A Professional
 Retirement Seminars
 Retirement Benefits Tax
 Retirement Living
 Relocation / Real Estate
 Retirement Jobs
Home | Annuity Calculation-CSRS | CSRS Offset Basic Annuity Calculation

CSRS Offset Basic Annuity Calculation

Printer-Friendly Format

The basic annuity for a CSRS Offset employee is calculated in the same as that for a regular CSRS employee:

  • 1.5% x High-3 x first five years of service
  • plus 1.75% x High-3 x next five years of service
  • plus 2.0% x High-3 x all years of service over 10

CSRS Offset Annuity Reduction

Your CSRS Offset annuity is reduced by the portion of your total Social Security benefit that is payable based on federal service performed after 1983 while covered by both the CSRS and Social Security.

Your annuity will not be reduced by any portion of your Social Security benefit that is based on service other than CSRS Offset employment.

When Will the CSRS Offset Annuity Be Reduced?

Normally, OPM will contact SSA when you are close to age 62 (the normal age of Social Security eligibility), to obtain an entitlement determination. If you are eligible to receive Social Security benefits, SSA will provide OPM with information concerning your benefits. Please note that even if you do not apply for Social Security benefits when  first eligible, the reduction in your annuity must still be made if you are eligible for Social Security benefits.

If you retire at age 62 or later and already are entitled to Social Security benefits, the offset in your annuity will be made at retirement. If you never become eligible for Social Security benefits based on your own employment, there is no offset.

How is the Offset Computed?

The Social Security Administration takes the Federal earnings in the period(s) when you are covered by both Social Security and CSRS and computes a Social Security benefit with those earnings included, and then without those earnings included. These two amounts are sent to OPM so that we can determine the CSRS Offset amount.

Your CSRS benefit is computed as explained above. The offset reduction is then subtracted from the annuity rate to become your new gross annuity rate.

The offset reduction is the lesser of:

  1. the difference between the Social Security monthly benefit amount with and without CSRS Offset service (service after December 31, 1983, covered under the interim CSRS provisions or the CSRS Offset provisions); or
  2. the product of the Social Security monthly benefit amount, with federal earnings, multiplied by a fraction where the numerator is the employee's total CSRS offset service rounded to the nearest whole number of years and the denominator is 40. 
Social Security Benefit X

Total Years of Offset Service


In this example, the employee is age 62, and has 3 years and 8 months of offset service.

Computation 1

Social Security monthly benefit with offset service $600
Social Security monthly benefit without offset service $550
Difference $ 50

Computation 2

Social Security amount with federal earnings:
$600 X 4 years* = $2400 divided by 40 = $60
(*Nearest whole year to 3 years 8 months)

In this example the offset to the CSRS annuity would be $50, since that is the lesser amount.

Source:  OPM RI 83-13

·  CSRS Basic Annuity Calculation for Law Enforcement Officers and Firefighters
·  CSRS Basic Annuity Calculation for Regular Employees
·  High-3 Average Salary

Featured Columnist
Read federal retirement articles written by federal benefits expert and Certified Financial Planner, Edward Zurndorfer

Recent Articles & Resources
 5 Questions to Ask Before Transferring IRA and Retirement Funds To and From the Traditional TSP
 Senate Committee Approves Bill to Stop Wasteful Federal Employee Bonuses
 Largest Federal Employee Union Demands Lifetime Credit Monitoring in Wake of Data Breach
 Congratulations Graduates! Now Comes Your Final Test: How to Manage Your Finances
 NARFE Urges Congress to Support Proposed Rule Protecting TSP Participants