FERS basic annuity
How OPM calculates the FERS annuity
OPM computes your basic annuity from two numbers: your length of service and your high-3 average salary. To get the length of service, OPM adds all your periods of creditable service and then drops any fractional part of a month from the total. Your high-3 is the highest average basic pay you earned during any 3 consecutive years of service. That is usually your last three years, but an earlier period counts if your basic pay was higher then. Basic pay includes increases for which retirement deductions are withheld, such as shift rates, and leaves out overtime and bonuses.
The formula itself is short. Retiring under age 62, or at 62 or older with fewer than 20 years of service, you get 1 percent of your high-3 for each year of service. Retiring at 62 or older with 20 or more years, the rate rises to 1.1 percent. OPM's own examples: a $90,000 high-3 with 18 years at 62 pays 1% x $90,000 x 18 = $16,200 a year, or $1,350 a month; with 20 years it pays 1.1% x $90,000 x 20 = $19,800, or $1,650 a month. There is no maximum annuity under FERS.
Months count as twelfths of a year. OPM's worksheets turn the service into a retirement factor carried to six decimals, multiply it by the high-3, round the yearly amount to the cent and round the monthly amount down to the next lower dollar. The calculator follows the same steps, which is why its results match OPM's handbook examples to the penny.
| Service | 1% (under 62) | 1.1% (62+ with 20 years) | Special provision |
|---|---|---|---|
| 20 years | $20,000 | $22,000 | $34,000 |
| 25 years | $25,000 | $27,500 | $39,000 |
| 30 years | $30,000 | $33,000 | $44,000 |
| 35 years | $35,000 | $38,500 | $49,000 |
Yearly basic annuity on a $100,000 high-3 before any reduction, our calculation with the OPM formulas. Special provision: 1.7% for the first 20 years plus 1% for each year beyond 20.
Which retirement type you qualify for
The calculator reads your age on your last day of service and your years of service, then applies OPM's eligibility rules. An immediate, unreduced annuity needs age 62 with 5 years, age 60 with 20 years, or your minimum retirement age (MRA) with 30 years. At your MRA with at least 10 but fewer than 30 years you can retire under the MRA+10 provision, which carries an age reduction. Your MRA is between 55 and 57 depending on your year of birth, and 57 for anyone born in 1970 or later; the result card shows yours.
Early retirement, offered in certain involuntary separations and during a major reorganization or reduction in force, needs age 50 with 20 years or any age with 25 years, and the annuity is not reduced for age. Special provision employees (law enforcement officers, firefighters and air traffic controllers) can retire at 50 with 20 years or at any age with 25 years of covered service. If you leave before you qualify for an immediate annuity and have at least 5 years of creditable civilian service, you can get a deferred annuity at 62, or at your MRA with 10 or more years.
An immediate annuity starts on the first day of the month after you separate (5 U.S.C. 8464); after an involuntary separation it starts the day after separation. A deferred annuity starts the first day of the month after you meet the age requirement.
Unused sick leave adds service, not eligibility
For an immediate retirement, unused sick leave is added to the service used in the formula (5 U.S.C. 8415(m)). It never counts toward the years you need to retire or toward your high-3, and the calculator also leaves it out of the 20-year test for the 1.1 percent factor. OPM converts hours with a chart based on a 2,087-hour work year: 1,040 hours becomes 6 months, and 2,087 hours is one full year. After the sick leave is added, any odd days left over are dropped. OPM does not credit sick leave in a deferred retirement. To project how much sick leave you will have by your retirement date, use the federal sick leave calculator.
The MRA+10 age reduction
An MRA+10 annuity is reduced by 5/12 of 1 percent for each full month you are under 62 on the date the annuity begins, which is 5 percent a year. The reduction does not apply if you have 20 years of service and the annuity starts at 60 or later. You can postpone the start to any month between your MRA and 2 days before your 62nd birthday to shrink or remove the cut; set "Annuity starts" to Later to see the effect. If you wait past 62, OPM treats it as a deferred retirement that starts the first day of the month after your 62nd birthday, with no age reduction and no sick leave credit.
| Age when the annuity starts | Full months under 62 | Reduction |
|---|---|---|
| 57 | 60 | 25% |
| 58 | 48 | 20% |
| 59 | 36 | 15% |
| 60 | 24 | 10% |
| 61 | 12 | 5% |
Our calculation with the 5/12 of 1% a month rule from OPM and 5 U.S.C. 8415(h), for exact birthdays.
What the survivor benefit costs
If you are married, OPM reduces your annuity to pay for a survivor benefit unless your spouse consented to a smaller election. A full survivor annuity (50 percent of your annuity) costs 10 percent. A partial one (25 percent) uses half of your annuity as the base and costs 5 percent. OPM's handbook example: on a $9,000 annuity the full election costs $900 a year and the half-base election $450. The reduction is taken after any age reduction, and the survivor would receive 50 percent of the base you chose.
OPM's worked examples
These four cases come from OPM's CSRS and FERS Handbook. The calculator reproduces every figure in the table.
| OPM example | High-3 | Service | Factor | Basic annuity | Reductions | Monthly paid |
|---|---|---|---|---|---|---|
| Example 1: optional retirement at 60, full survivor | $53,221 | 31 years 2 months | 0.311667 | $16,587.23 | Survivor 10% | $1,244 |
| Example 2: MRA+10 at 58, half survivor base | $93,781 | 13 years 6 months | 0.135000 | $12,660.44 | Age .804167, survivor 5% | $806 |
| Firefighter, special provision, half base | $54,836 | 26 years | 0.400000 | $21,934.40 | Survivor 5% | $1,736 |
| Air traffic controller, full survivor | $58,906 | 20 years | 0.340000 | $20,028.04 | Survivor 10% | $1,502 |
Sources: OPM, CSRS and FERS Handbook, chapter 50 (FERS examples 1 and 2) and chapter 54 (examples 5 and 6).
Special provision employees
For law enforcement officers, firefighters and air traffic controllers retiring under the special provisions, OPM uses 1.7 percent of the high-3 for the first 20 years and 1 percent for each year beyond 20. There is no age reduction, and the 1.1 percent formula never applies. A firefighter in OPM's handbook with 26 years and a $54,836 high-3 gets a factor of .400000 and a basic annuity of $21,934.40.
Cost-of-living adjustments and the supplement
FERS cost-of-living adjustments are not paid until age 62, except for disability, survivor and special provision retirements. The FERS COLA follows the consumer price index, capped: when the CPI rise is between 2 and 3 percent, the FERS COLA is 2 percent. For 2026 OPM set it at 2.0 percent for FERS and 2.8 percent for CSRS, effective December 1, 2025. Your first COLA is prorated, one-twelfth for each month you received the annuity.
If you retire before 62 at your MRA with 30 years, at 60 with 20 years, under the special provisions or under an early or discontinued service retirement at or after your MRA, you may also receive the FERS annuity supplement until 62. MRA+10 and deferred retirees do not get it. Estimate it with the FERS supplement calculator. For the tax side, the retirement income tax calculator and the guide to pension and annuity withholding explain what is withheld, and the FERS paycheck deductions guide explains what you pay in while working. Your high-3 comes from your basic pay, which the GS pay calculator shows by grade and step.
Questions
FERS retirement calculator FAQ
How is the FERS annuity calculated?
OPM multiplies your high-3 average salary by 1 percent for each year of creditable service, or by 1.1 percent if you retire at 62 or older with at least 20 years. Service is counted in years and months, with odd days dropped. The yearly amount is then reduced for any MRA+10 age reduction and survivor election, and the monthly payment is rounded down to the dollar.
When do I get the 1.1 percent multiplier?
When you retire on an immediate annuity at age 62 or older with at least 20 years of service. It does not apply to deferred annuities or to special provision retirements, and the calculator does not use unused sick leave to reach the 20 years.
Does unused sick leave count toward my FERS annuity?
Yes, for an immediate retirement. OPM adds it to the service in the formula using a 2,087-hour chart, so 1,040 hours adds 6 months. It does not count toward eligibility or the high-3, and it is not credited in a deferred retirement.
How much does the survivor benefit reduce my FERS annuity?
A full survivor annuity, worth 50 percent of your annuity to your spouse, reduces your annuity by 10 percent. A partial one, worth 25 percent, reduces it by 5 percent. Electing less than the full survivor benefit requires your spouse's consent.
How much is the MRA+10 penalty?
Five-twelfths of 1 percent for each full month you are under 62 when the annuity starts, or 5 percent a year. Starting at 58 costs 20 percent. With 20 years of service, starting at 60 or later removes the reduction, and you can postpone the start to any month before 62.
When do FERS retirees get cost-of-living adjustments?
Regular FERS retirees receive COLAs starting at 62. Disability, survivor and special provision annuities receive them earlier. For 2026 the FERS COLA was 2.0 percent, and the first COLA after retirement is prorated by the months you were retired.
- Sources: OPM, FERS computation, eligibility and types of retirement · OPM, cost-of-living adjustments (2026) · OPM, CSRS and FERS Handbook, chapters 50 and 54 · 5 U.S.C. 8415 and 8464.
- 🔄 Last updated September 26, 2026
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