Your FERS pension is one of the most valuable benefits of a federal career, a guaranteed, inflation-adjusted income stream that will pay you for the rest of your life. Understanding how it’s calculated now gives you the power to make decisions that can meaningfully increase what you receive.
The Basic Formula
The FERS annuity is calculated using three variables: your High-3 average salary, your years of creditable service, a multiplier based on your age, and years of service at retirement.
The formula is: High-3 Average Salary x Years of Creditable Service x Multiplier = Annual Annuity
For most federal employees, the multiplier is 1%. If you retire at age 62 or later with at least 20 years of creditable service, that multiplier increases to 1.1%. That’s a 10% boost to your pension for the rest of your life.
What Is Your High-3?
Your High-3 is the average of your highest 36 consecutive months of basic pay. For most employees, this is the final three years before retirement, but it can be any consecutive three-year period during your career if your pay was higher at an earlier point.
Your High-3 includes your base salary and locality pay, but does not include overtime, bonuses, awards, or other premium payments. This distinction matters — federal employees sometimes assume their total compensation feeds into the High-3 when it does not.
One important nuance worth understanding: because the High-3 is an average of 36 consecutive months, a pay increase in the final months before retirement might have less impact than expected. If you receive a significant raise in your last three months before retirement, those three months represent only 3/36 of the 36-month calculation, not one full year.
What Counts as Creditable Service?
Your years of creditable service include all time in a FERS-covered position where retirement deductions were withheld from your pay. It can also include military service time if you have completed the required military service deposit, and unused sick leave, which is converted into additional months of service credit at the time of retirement.
Sick leave does not count toward your retirement eligibility — you cannot use it to qualify for retirement earlier — but it does increase your annuity calculation. Approximately 174 hours of unused sick leave converts to one additional month of creditable service. For those with a substantial sick leave balance, that can add a boost to your pension.
Putting the Numbers Together
Example: $90,000 High-3 Salary
| Scenario | Formula | Annual | Monthly |
| 25 years, before age 62 | $90,000 x 25 x 1% | $22,500 | ~$1,875 |
| 25 years, age 62 or later | $90,000 x 25 x 1.1% | $24,750 | ~$2,063 |
| 30 years, age 62 or later | $90,000 x 30 x 1.1% | $29,700 | ~$2,475 |
Waiting until age 62 with 25 years of service adds $2,250 per year — for life.
What Can Reduce Your Annuity
Several factors can reduce your FERS annuity:
Retiring under the MRA+10 provision, meaning you have reached yourMRA with 10 to 29 years of service triggers a permanent 5% reduction for every year you are under age 62 at retirement.
Electing a survivor annuity for your spouse reduces your pension by 10% for a full survivor benefit or 5% for a partial one.
Part-time service during your career results in a prorated annuity based on your actual hours worked compared to a full-time schedule.
Why This Matters for Your Planning
The FERS formula rewards time and patience. Working until age 62 rather than your MRA can increase your annuity by adding more years of creditable service and by unlocking the 1.1% multiplier. For many federal employees, understanding that trade-off changes the retirement date conversation entirely.
A Federal Retirement Consultant (FRC®) can help you run your specific numbers, model different retirement scenarios, and identify strategies that maximize your annuity. Schedule your complimentary benefits review today.
