Last Updated: November 11, 2026 Reading Time: 9 min

A FERS retiree makes two big health-and-income decisions on separate forms, years apart: when to claim Social Security, and when to take Medicare Part B. They are tied together by three clocks. The FERS supplement stops at 62. The Part B window depends on whether your FEHB comes from a job. And the Medicare surcharge called IRMAA reads your income from two years earlier.

Here is how they line up at four common retirement ages.

Your path FERS supplement Social Security (share of full benefit) Part B window Where IRMAA can bite
1. Retire at 57 with 30 years; claim Social Security at 62; Part B at 65 Paid until 62; work after retiring can reduce it 70% at 62, permanently 7-month window around 65; enrolled automatically because Social Security is already paid TSP withdrawals or Roth conversions in any year set the premium two calendar years later
2. Retire at 62; claim Social Security at 62 None 70% Same as path 1 Your final working year sets the premium for the calendar year two years later; whether you have Part B yet depends on your birthday
3. Retire at 62; delay Social Security to 70 None 124% at 70 7-month window; you must sign up yourself Highest risk: TSP withdrawals that bridge you to 70 set your premiums from 65 to 70
4. Keep working past 65 with FEHB; retire at 67 None 100% at 67 (124% if you wait to 70) 8-month Special Enrollment Period after the job-based coverage ends Biggest single spike: final salary plus the annual leave payout

Assumes you were born January 2, 1960 or later (full retirement age 67) and file single. 2026 rules.

Clock 1: The FERS Supplement Stops at 62

The supplement ends at 62 by law, whether or not you file for Social Security. It is paid through the month you turn 62, or ends earlier if you could get Social Security earlier.

Retire at 62 or later and there is no supplement to bridge anything. The supplement goes only to an annuity that starts before 62: retirement at your Minimum Retirement Age with 30 years, or at 60 with 20, and a few special cases. MRA+10 retirees do not get it either. Born 1970 or later, your MRA is 57.

It has an earnings test. Earn more than the Social Security exempt amount while on the supplement and OPM takes back $1 for every $2 over. In 2026 the limit is $24,480; for 2027 it rises to $25,560. The cut for 2026 earnings hits supplement payments from July 2027 through June 2028.

Wages before your retirement date, and pension or TSP income, are not supplement "earnings."

Our FERS supplement cliff post covers the drop in income at 62, and the FERS supplement calculator estimates your amount.

Clock 2: Social Security Between 62 and 70

Born January 2, 1960 or later, your full retirement age is 67. Each month you claim before then shaves a fixed fraction off your benefit for life, and each month you wait past it adds a credit until 70.

  • Claim at 62: 70% of your full benefit, permanently.
  • Claim at 67: 100%.
  • Claim at 70: 124%. Credits stop at 70.

The Social Security earnings test also applies if you claim before 67 and keep working: $24,480 in 2026 and $25,560 in 2027, with a higher limit of $65,160 in 2026 and $67,920 in 2027 in the year you reach full retirement age.

WEP and the GPO no longer exist. The Social Security Fairness Act repealed both for benefits payable for months after December 2023, so a FERS or CSRS pension no longer reduces your own Social Security or a spousal benefit. The delayed credits post shows what bridging from 62 to 70 costs out of the TSP.

Clock 3: Which Part B Window You Get

Still working at 65 with FEHB (path 4). You can skip Part B while your FEHB comes from your job. Working with FEHB at 65 opens an 8-month window that starts when the job-based coverage ends. Months on FEHB through current employment don't count toward any penalty. If you are in an HDHP, stop HSA contributions before your Medicare coverage starts. If you sign up for Medicare after 65, premium-free Part A can start up to six months before you apply, so stop contributions six months before you apply.

Already retired at 65 (paths 1, 2 and 3). Retiree FEHB is not job-based coverage for Medicare. A retiree turning 65 uses the regular 7-month window: the 3 months before your 65th birthday month, that month and the 3 months after. If your birthday is on the 1st of a month, count from the month before. Sign up in the three months before the month your Medicare eligibility starts to have Part B from day one.

The penalty is permanent. The surcharge is 10% of the premium for each full 12 months of countable delay after your enrollment window closes, so 36 countable months adds 30%, for as long as you have Part B.

Automatic or not. If you already draw Social Security at 65 (paths 1 and 2), Part B starts automatically unless you decline it. If you are delaying Social Security (path 3), sign up yourself; don't assume it happens.

Adding Part B never lowers your FEHB premium. Whether it is worth the cost on top of FEHB depends on your income and plan; our FEHB and Medicare Part B guide works through that.

Clock 4: IRMAA Reads Your Income From Two Years Back

Your 2026 Part B premium is set by your 2024 tax return. In 2026 the standard Part B premium is $202.90 a month. Above $109,000 of income for a single filer ($218,000 joint), the surcharge starts: $284.10 a month at the first step. A single retiree with 2024 MAGI of $178,000 pays $527.50 a month for Part B in 2026.

Anything that raises AGI (final salary, a leave payout, TSP withdrawals, Roth conversions) plus muni interest counts.

That two-year gap is why the retirement age matters:

  • Count calendar years, not ages. Your final salary and leave payout land in your retirement tax year, which sets the premium for the calendar year two years later. Retire in a year you turn 62 or 63 and that later year may come before or after your Part B starts, depending on your birthday.
  • Path 4 is the biggest spike, because salary at 65 to 67 plus the leave payout can push you up several steps in a year you already have Part B.
  • Bridging to 70 with TSP withdrawals (path 3): each year's withdrawals set the premium two years later, from 65 to 70.

The appeal that works, and the one that doesn't. If your income dropped because you retired, you can ask SSA to use a newer year. Retirement counts as a work stoppage for an IRMAA appeal. A Roth conversion or a large TSP withdrawal is not on SSA's list of life-changing events. Our SSA-44 guide shows how to file.

How Part B Gets Paid

Once you draw Social Security, Part B comes out of the check. A "hold-harmless" rule can keep a Part B increase from shrinking your net Social Security payment, if you meet its conditions, including having Part B taken from your Social Security in the prior year. The hold-harmless shield covers only people already drawing Social Security, and never IRMAA payers.

Delaying Social Security doesn't mean paying Part B by hand: the law lets OPM take it from your annuity. Without a Social Security check, though, you lose the hold-harmless protection.

As of November 11, 2026, we had not found an official 2027 Part B premium in CMS's sources; the figures here are 2026 rates.

Run Your Own IRMAA Year

Enter a year's projected wages, pension, gross Social Security, TSP withdrawals and any Roth conversion in the IRMAA cliff calculator. It applies the 2026 brackets to that year's income to show which IRMAA tier it lands in and the Part B and Part D surcharge at today's rates. The premium year it affects is two years later, and future brackets and premiums will differ. Run your retirement year and each bridge year before you decide when to claim.

Frequently Asked Questions

I retire at 57. Do I need to sign up for Part B when I turn 65 even though I have FEHB?

Yes, if you want Part B without a penalty. Your window is the 7-month Initial Enrollment Period around your 65th birthday month (counted from the month before if your birthday is on the 1st). Retiree FEHB does not give you the 8-month Special Enrollment Period, and missing the initial window costs 10% of the Part B premium for each full 12 months you went without it.

Does the FERS supplement continue if I wait until 70 for Social Security?

No. The supplement ends at 62 by law, whether or not you file for Social Security.

I'm retiring at 62. How long does the supplement last?

You don't get one. The supplement goes only to an annuity that starts before 62.

Will my retirement-year leave payout raise my Medicare premium?

It can, because IRMAA reads the tax year two years before the premium year. Whether that later year is one you have Part B depends on your birthday, not just your retirement age. If it does, retirement counts as a work stoppage, so you can ask SSA to use a newer, lower-income year.

If I delay Social Security, how do I pay Part B?

By a bill, or by a deduction from your FERS annuity, which the law allows OPM to take. Either way you lose the hold-harmless protection that can apply to people who have Part B taken from their Social Security.

What is the earnings limit on the FERS supplement?

The same as Social Security's annual exempt amount: $24,480 in 2026 and $25,560 in 2027. OPM reduces the supplement $1 for every $2 over, starting the July after the year of the earnings.

Does WEP still cut my Social Security because of my federal pension?

No. The Social Security Fairness Act repealed WEP and the GPO for benefits payable for months after December 2023.

Does adding Part B lower my FEHB premium?

No. Your FEHB premium is the same with or without Part B.

Sources