FERS, the Federal Employees Retirement System, pays you from three sources at once: a monthly pension figured from your high-3 and years of service, Social Security, and your Thrift Savings Plan account. The date you leave changes all three, so you plan them together.
An annuity estimate is full of acronyms: MRA, high-3, SRS, BEDB, FEHB. One picture makes the rest of this section easier. FERS is a three-legged stool. One leg is a pension. One leg is Social Security. One leg is your TSP. Each leg has its own rules, but the stool only stands when all three are the right length at the same time.
This page is the map. It explains what each leg does, how they lean on each other, and which guide to read next for the decision you are facing. Every government figure is dated to the day we checked it at its source.
01What is FERS?
FERS is the retirement system for most federal civilian employees first hired on or after January 1, 1984. Congress built it in 1986 to replace the older Civil Service Retirement System for new hires, and it took full effect in 1987. Employees hired before 1984 generally stayed in CSRS or CSRS Offset unless they switched during an open season. If that describes you, the CSRS guide covers your rules.
The big design choice behind FERS is balance. CSRS put almost everything into one large pension. FERS spreads the load: a smaller pension, plus Social Security, plus a savings account the government pays into. That makes FERS more portable. If you leave government early, the TSP and the Social Security credit come with you, and the pension can wait for you as a deferred annuity.
- Basic annuityThe FERS pension. A monthly payment for life, figured from your high-3, your years of service and a multiplier.
- Social SecurityThe same program private-sector workers pay into. Your federal wages earn Social Security credit under FERS.
- Thrift Savings Plan (TSP)A defined-contribution account, like a 401(k), with an automatic agency contribution and matching.
- High-3Your highest average basic pay over any three consecutive years of service. Locality pay counts; overtime and bonuses do not.
- MRAMinimum Retirement Age. Between 55 and 57 depending on the year you were born.
- Creditable serviceThe years and months the pension formula multiplies, including some military and part-time time.
02What are the three parts of FERS, and what does each one pay?
The three parts are the basic annuity, Social Security and the TSP, and each one replaces a different slice of your paycheck. The pension gives you a steady base. Social Security adds an inflation-adjusted benefit that can start as early as 62. The TSP is the flexible money you control.
| Part | Who funds it | How the amount is set | When you can start |
|---|---|---|---|
| Basic annuity | You and your agency, through payroll | 1% of high-3 per year of service, or 1.1% at 62 with 20+ years | MRA, 60 or 62, depending on service |
| Social Security | You and your agency, through FICA | Your lifetime earnings record and claiming age | As early as 62, reduced before full retirement age |
| TSP | Your contributions plus agency 1% and match | What went in and how the funds performed | After you separate, with age rules on penalties |
Source: OPM FERS computation and eligibility pages (retrieved 2026-10-11); TSP contribution rules (retrieved 2026-07-05).
The pension is the leg most people underestimate. At 1 percent per year, a 30-year career replaces about 30 percent of your high-3. That number surprises people who expected CSRS-sized checks. It is not a flaw; it is the design. FERS expects the other two legs to carry the rest.
The TSP is where the agency puts real money in your pocket. FERS employees receive an automatic agency contribution of 1 percent of basic pay, even if they contribute nothing. On top of that, the agency matches your contributions dollar for dollar on the first 3 percent of pay and 50 cents on the dollar on the next 2 percent. Contributing at least 5 percent captures the full match (TSP, retrieved 2026-07-05). Our TSP guide walks through the funds and withdrawal rules.
03How do the three parts interact?
The three parts interact through one decision: the month you separate. Your retirement date sets your pension multiplier, decides whether the FERS supplement is paid, starts the clock on TSP withdrawals, and shapes when Social Security makes sense to claim. Move the date and every leg moves with it.
Here are the four connections that matter most.
- Age 62 links the pension and the multiplier. Separate at 62 or later with at least 20 years and the multiplier rises from 1 percent to 1.1 percent on every year you worked, not just the later ones.
- The supplement links the pension and Social Security. If you retire on an immediate, unreduced annuity before 62, a supplement approximating your federal-service Social Security benefit is paid until 62. It stops at 62 whether or not you claim Social Security.
- The pension's COLA links to your age. Most regular FERS retirees receive no cost-of-living adjustment until 62, so the TSP and the supplement often carry inflation risk in the early years.
- Health coverage links to the pension. To keep FEHB in retirement you generally must retire on an immediate annuity after five years of continuous FEHB enrollment. A deferred annuity does not carry FEHB.
That last link is easy to miss. Health insurance is not a leg of the stool, but it rides on the pension leg. Leave too early and take a deferred annuity, and you lose the right to carry Federal Employees Health Benefits into retirement (OPM, retrieved 2026-07-05). The FEHB guide explains the five-year rule in detail.
Every FERS retirement plan is really a date. Pick the month, and the pension, the supplement, Social Security and your health coverage all fall into place around it.
04How is the FERS pension figured?
The FERS basic annuity is your high-3 average salary, times your years of creditable service, times a multiplier of 1 percent, or 1.1 percent if you separate at 62 or later with at least 20 years (OPM, retrieved 2026-10-11). Service counts in full years and months; leftover days drop off.
Three inputs, one multiplication. What makes it feel complicated is that each input has rules of its own. Which pay counts toward the high-3? Does unused sick leave count? What about military time? The FERS annuity guide takes each input in turn and works the numbers on a full example.
For a fast estimate on your own inputs, the FERS pension estimator runs the formula with and without a survivor election.
05When can you retire under FERS?
You can retire under FERS on an immediate, unreduced annuity at your Minimum Retirement Age with 30 years of service, at 60 with 20 years, or at 62 with 5 years (OPM, retrieved 2026-10-11). You can also leave at your MRA with 10 years, but that MRA+10 annuity is reduced 5 percent for each year you are under 62 when it starts.
Your MRA depends on your birth year. It is 55 for anyone born before 1948, steps up two months at a time, sits at 56 for anyone born from 1953 through 1964, and reaches 57 for anyone born in 1970 or later (OPM, retrieved 2026-10-11). The MRA finder gives you your exact age and month.
- 01
Find your MRA
Your birth year sets it. Write down the month you reach it.
- 02
Count your creditable service
Include military time only if the deposit is paid, and remember that unused sick leave counts in the computation but not for eligibility.
- 03
Match yourself to a combination
MRA with 30, 60 with 20, 62 with 5, or MRA with 10 and a reduction.
- 04
Check the 62-and-20 line
If you are close, see what working to 62 does to the multiplier.
- 05
Check FEHB
Confirm you will have five years of continuous enrollment by your last day.
The eligibility guide covers the full MRA table, deferred and postponed retirement, and what happens if you leave before you qualify. Certain jobs, such as law enforcement, firefighting and air traffic control, follow earlier rules and a richer formula; the special provisions guide covers them.
Your record, not our example
Want this run on your own numbers?
A Federal Retirement Consultant (FRC) works through your own records with you 1:1. The review is free and nothing is booked until you choose a time.
06What other FERS benefits and decisions should you know about?
Beyond the basic annuity, FERS includes a supplement for some early retirees, survivor protection for your spouse, a disability retirement, and a way to buy credit for military service. Each one is a separate decision, and several of them are permanent once made.
- The FERS supplementA bridge payment for some retirees under 62, with an earnings test if you work.
- Survivor benefitsThe election that decides your spouse's income and whether they keep FEHB. It is permanent.
- Special provisionsEarlier retirement and a 1.7 percent multiplier for covered law enforcement, firefighters and controllers.
- Disability retirementA pension for employees who can no longer perform their job, after 18 months of service.
- Military buybackPaying a deposit so active-duty years count toward your pension. Must be done before you retire.
- CSRS and CSRS OffsetThe older system, its formula and how it compares to FERS.
Two of these decisions catch people more than any others. The survivor election is made once, at retirement, and it also decides whether a surviving spouse can keep federal health coverage. And the military deposit must be paid before you separate; after that, the window closes for good.
07What does Social Security add under FERS?
Social Security is the second leg of FERS, and your federal wages earn credit toward it just as private-sector wages do. Your benefit is based on your lifetime earnings record and the age you claim, and you can start as early as 62 at a reduced amount.
Because FERS employees pay into Social Security, the pension is smaller than a CSRS pension. That trade is the whole architecture of FERS. The supplement exists to cover the gap for people who retire on an immediate, unreduced annuity before they can draw Social Security. Once you reach 62, the supplement stops and the decision about when to claim Social Security is yours.
Claiming age is one of the biggest levers in a FERS plan. Claim at 62 and the benefit is permanently reduced. Wait past full retirement age and it grows. The pension and the TSP often fund the years between, which is why these decisions belong on one sheet of paper. Our Social Security guide covers claiming in more depth.
08Where should you start?
Start with the question closest to your calendar. If retirement is more than ten years away, the work is about building the legs: the full TSP match, continuous FEHB enrollment, and any military deposit paid before the interest-free period ends (see the buyback guide). If retirement is within five years, the questions are about timing: your MRA, the 62-and-20 line, the supplement and the survivor election.
- More than 10 years out. Contributing 5 percent to the TSP captures the full match, and a military deposit is worth looking into if you served.
- Five to 10 years out. Find your MRA, count your service, and request an annuity estimate from your agency.
- Within five years. Compare retirement months, check FEHB continuity, and read up on the survivor election.
- Within one year. Gather your SF-50s, confirm your service history and decide on survivor coverage with your spouse.
- Leaving before you qualify. A refund of contributions gives up the deferred annuity, so it helps to know what that annuity is worth first.
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09Moving forward with your FERS plan
FERS rewards planning because its parts are connected. A month's difference in your last day can move your multiplier, start or stop the supplement, and change how long your TSP has to carry you. None of that is hidden; it is just spread across three sets of rules.
You can work through it on your own with the guides above. Or you can sit down with someone who works with these rules every week.
FFEBA is an education organization. If you want someone to look at your own numbers, we can match you with a Federal Retirement Consultant (FRC), a professional trained on federal benefits. The FRC designation is listed with FINRA. The first review is free, nothing is booked until you choose a time, and you are never obligated to work with anyone we introduce. Get matched with an FRC.
Reviewed by the FFEBA education team. Last reviewed October 2026.
Sources
- U.S. Office of Personnel Management, FERS eligibility, retrieved 2026-10-11
- U.S. Office of Personnel Management, FERS computation, retrieved 2026-10-11
- U.S. Office of Personnel Management, FERS types of retirement, retrieved 2026-10-11
- U.S. Office of Personnel Management, cost-of-living adjustments, retrieved 2026-07-05
- U.S. Office of Personnel Management, CSRS/FERS Handbook, retrieved 2026-07-05
- Thrift Savings Plan, making contributions, retrieved 2026-07-05
- U.S. Office of Personnel Management, FEHB in retirement, retrieved 2026-07-05
Every government figure on this page carries its source and retrieval date. Worked examples are educational estimates on the assumptions shown, not a projection of any person's benefit. FFEBA is an education organization, not a financial advisor.
