FEHB & Medicare The Part B Decision

2027 IRMAA brackets preview: what your 2025 income already decided

The Medicare surcharge you will pay in 2027 was set by the tax return you filed this spring. CMS will not publish the official 2027 brackets until November, but the indexing method is public, the 2026 brackets are final, and the Trustees have already projected the 2027 Part B premium. That is enough to see where you land, roughly what it costs, and, if you are within a few thousand dollars of a cliff, what you can still do about 2028.

$109,000
2026 first-tier threshold, single (final; $218,000 joint)
CMS, Nov 14, 2025
~$112,000
Projected 2027 first-tier threshold, single (~$225,000 joint)
Estimate; CMS final in Nov 2026
$218.60
Projected 2027 standard Part B premium (2026: $202.90)
2025 Medicare Trustees Report
2025
Tax year that determines your 2027 surcharge
SSA, two-year lookback

1. The two-year lookback: 2025 sets 2027

The income-related monthly adjustment amount, IRMAA, is a surcharge added to your Medicare Part B premium and to your Part D drug coverage premium when your modified adjusted gross income exceeds a threshold. The Social Security Administration determines it using the most recent tax return the IRS can supply, which in the fall of 2026, when 2027 premiums are set, is the return for tax year 2025. That is the two-year lookback, and it has a consequence people miss every year: your 2027 IRMAA is already decided. The Roth conversion you are considering this fall affects 2028. The TSP lump sum you took in 2025 affects 2027, and it is too late to undo it.

For a full explanation of how IRMAA works, the appeal process, and the 2026 figures in detail, see the 2026 IRMAA guide and IRMAA explained. This article is narrower: it is about what 2027 will look like, and what you can still influence.

2027 IRMAA tier = f(2025 MAGI, 2025 filing status)
2025 MAGI = 2025 AGI + tax-exempt interest

Set by SSA in fall 2026 · Billed January–December 2027 · Appealable only for a qualifying life event

2. The final 2026 brackets

CMS announced the 2026 figures on November 14, 2025. The standard Part B premium is $202.90 a month; the Part B deductible is $283. IRMAA is charged per person, so a married couple both on Medicare pays each amount twice.

2024 MAGI, single2024 MAGI, jointPart B total / moPart D surcharge / moAnnual surcharge per person
≤ $109,000≤ $218,000$202.90$0$0
$109,001 – $137,000$218,001 – $274,000$284.10$14.50$1,148
$137,001 – $171,000$274,001 – $342,000$405.80$37.50$2,885
$171,001 – $205,000$342,001 – $410,000$527.50$60.40$4,620
$205,001 – $499,999$410,001 – $749,999$649.30$83.30$6,356
≥ $500,000≥ $750,000$689.90$91.00$6,936

Two structural facts drive everything else. First, the tiers are cliffs: $109,000 pays nothing, $109,001 pays $1,148 for the year. Second, the surcharge tiers are defined as fixed percentages of the program’s cost. The standard premium covers 25% of Part B costs; the five tiers pay 35%, 50%, 65%, 80%, and 85%. That is why each tier’s total premium is a fixed multiple of the standard premium: 1.4×, 2.0×, 2.6×, 3.2×, and 3.4×. Change the standard premium and every tier moves with it.

3. How the 2027 thresholds are indexed

Under the Social Security Act, the first four income thresholds are adjusted each year by the percentage change in the Consumer Price Index for All Urban Consumers (CPI-U), measured over the twelve-month average ending in August, and rounded to the nearest $1,000. The fifth threshold, $500,000 single and $750,000 joint, was frozen by the Bipartisan Budget Act of 2018 and does not begin indexing until 2028. The 2026 thresholds rose about 3% from 2025 under this method.

The CPI-U figures that set the 2027 thresholds cover September 2025 through August 2026. Through July 2026, twelve-month inflation has been running between 3.4% and 3.5%; the August figure arrives on September 11. A full-year average in the low-3% range is therefore the reasonable planning assumption, which would move the first single threshold from $109,000 to roughly $112,000 and the first joint threshold from $218,000 to roughly $225,000. Rounding to $1,000 means the projection could land a thousand dollars either way; the estimator below lets you change the assumption.

The standard Part B premium is set separately by CMS, based on projected Part B spending. The 2025 Medicare Trustees Report projected $218.60 for 2027, a 7.7% increase over 2026. Recent years have run above the Trustees’ projections, so treat that as a floor rather than a ceiling.

4. Projected 2027 brackets and premiums

Applying a 3.0% index to the 2026 thresholds and the Trustees’ $218.60 base premium. Part D surcharges are indexed by the same method and shown to the nearest ten cents. Every figure in this table is an estimate until CMS publishes the final amounts; this page will be updated when they do.

2025 MAGI, single (projected)2025 MAGI, joint (projected)Part B total / moPart D surcharge / moAnnual surcharge per person
≤ ~$112,000≤ ~$225,000~$218.60$0$0
~$112,001 – $141,000~$225,001 – $282,000~$306.00~$14.90~$1,228
~$141,001 – $176,000~$282,001 – $352,000~$437.20~$38.60~$3,086
~$176,001 – $211,000~$352,001 – $422,000~$568.40~$62.20~$4,944
~$211,001 – $499,999~$422,001 – $749,999~$699.50~$85.80~$6,801
≥ $500,000 (fixed)≥ $750,000 (fixed)~$743.20~$93.70~$7,420

Note the shape of the change. The thresholds move up about $3,000 to $6,000 per tier, which is small relief. The premiums move up 7.7% across every tier, which is the larger effect. A retiree in the first tier pays about $80 more for the year in 2027 than in 2026 even if nothing about their income changes. And because the hold-harmless provision that limits Part B increases for people on Social Security does not apply to anyone paying IRMAA, every surcharge payer absorbs the full premium increase regardless of the COLA.

5. Estimate your 2027 surcharge

Enter your 2025 modified adjusted gross income (adjusted gross income from line 11 of your 2025 Form 1040, plus any tax-exempt interest from line 2a) and your 2025 filing status. The tool shows the tier you would fall in under the final 2026 brackets and under the projected 2027 brackets, the monthly cost of each, and how far you sit from the next cliff.

Try it: 2027 IRMAA estimator

Where does your 2025 income land you?

Result
Tier
On final 2026 brackets and premium
On projected 2027 brackets and premium
Distance to next cliff

Per person, per month. 2026 figures are final CMS amounts. 2027 thresholds, premium, and Part D amounts are estimates; CMS publishes final figures in November 2026. Married filing separately uses different thresholds not modeled here.

6. What counts as income, federal edition

MAGI for IRMAA is your adjusted gross income plus tax-exempt interest. For a federal retiree, nearly every income stream is inside that number.

Income sourceCounts toward IRMAA MAGI?Note
FERS or CSRS annuityYesTaxable portion, which is nearly all of it
FERS supplementYesFully taxable while paid (ends at 62)
Social SecurityYes, taxable portionUp to 85% is included in AGI
Traditional TSP withdrawals and RMDsYes100% taxable; RMDs cannot be skipped
Roth conversionsYes, in the year convertedThe most common cause of a one-year spike
Roth TSP and Roth IRA qualified withdrawalsNoThe reason to convert before 63
Municipal bond interestYesTax-exempt, but added back for IRMAA
VA disability compensationNoNot in AGI
FEHB premiumsNo effectPaid after tax in retirement; not a deduction
Annual leave lump sumYesLands in the year of separation; watch the year-two bill
Capital gains, including a home sale above the exclusionYesQualified charitable distributions after 70½ reduce it

Put those together for a typical federal couple: two annuities of $36,000 and $28,000, Social Security of $60,000 with 85% taxable, and $40,000 of RMDs. MAGI is $155,000, comfortably under the joint threshold. Add a $70,000 Roth conversion in the same year and MAGI is $225,000, which under the projected 2027 joint threshold of ~$225,000 is exactly on the line. One dollar more and both spouses pay Tier 1: about $2,450 for the household. That is why conversions get planned to the threshold and not past it, as the IRMAA cliff guide and the conversion ladder both stress.

The retirement-year trap

The year you retire usually contains a partial year of salary, the annual leave lump sum, and possibly a TSP withdrawal to bridge the OPM interim-pay period. It is often your highest-income year, and it sets your IRMAA two years later, exactly when your income has fallen to pension level. That is the situation the SSA-44 appeal in section 7 exists for, and retirement is a qualifying event.

Three federal households, projected 2027

Using the projected 2027 brackets and premiums:

Household2025 MAGIProjected 2027 tierHousehold surcharge, 2027What set it
Single GS-12 retiree: $34,000 pension, $26,000 Social Security (85% taxable), $22,000 TSP installments$78,100None$0Ordinary retirement income; $34,000 of room under the cliff
Retired GS-14 couple: $58,000 + $31,000 pensions, $64,000 Social Security, $36,000 RMDs$179,400None$0Comfortable at $45,000 under the joint threshold, until the first spouse dies
Same couple, but 2025 was his final working year: $148,000 salary, $27,000 leave payout, her $31,000 pension$206,000 + $18,000 TSP bridge draw = $224,000None, by $1,000$0Retirement-year income; a $2,000 larger TSP draw would have cost about $2,450. Had they crossed, SSA-44 would apply because he retired.
Widowed GS-14 retiree, first full year filing single: $58,000 pension, $40,000 survivor Social Security, $36,000 RMDs, $20,000 survivor annuity$148,000Tier 2~$3,086Income fell by a third; thresholds fell by half. The widow’s penalty.

The fourth row is the one that surprises people. Nothing about her situation looks like “high income,” and two years earlier the same household paid no surcharge. Filing single after a spouse’s death is the most common way a federal retiree enters IRMAA for the first time, and it is the reason the survivor planning in the widow’s penalty guide includes IRMAA alongside the tax brackets.

Married filing separately

Couples who file separately and lived together at any point in the year face a much harsher table: the first surcharge tier begins at the same $109,000 (projected ~$112,000) but jumps straight to the fourth-tier premium of $649.30 (projected ~$699.50) above it, with only the top tier, above $403,000, beyond that. There is almost never a reason for a Medicare-age federal couple to file separately, and IRMAA is one more on the list.

7. The SSA-44 appeal

If your 2025 income was high because of something that has since changed, you may not have to pay the 2027 surcharge it implies. Form SSA-44, “Medicare Income-Related Monthly Adjustment Amount – Life-Changing Event,” asks SSA to use a more recent year’s income instead. The recognized events are: marriage; divorce or annulment; death of a spouse; work stoppage; work reduction; loss of income-producing property (through circumstances beyond your control, not sale); loss of pension income; and an employer settlement payment. Retirement is a work stoppage. A federal employee who retired in 2025 or 2026 and whose 2027 IRMAA is based on a full year of GS-14 salary qualifies.

What does not qualify: a Roth conversion, a TSP lump sum, a home sale, capital gains, or any other one-time income that was your own decision. If your 2025 spike was one of those, the 2027 surcharge stands. It lasts one year; 2028 will be based on your 2026 income.

File the SSA-44 with proof of the event (your retirement SF-50, for example) and an estimate of your current-year income. You can file as soon as you receive the IRMAA determination letter in late 2026, and you can file for the current year even before the tax return proving the lower income exists. The SSA-44 guide walks through the form line by line.

8. Managing 2028 and beyond

You cannot change 2027. You can change 2028, because it is set by what you do between now and December 31, 2026. The levers, roughly in order of size for a federal retiree:

Watch two dates. On September 11, 2026 the August CPI-U completes the twelve-month average that sets the 2027 thresholds; the projection above will be replaceable with arithmetic that day. In November 2026 CMS publishes the final 2027 premium and bracket table, and SSA determination letters follow. This page will be updated at both points.

9. Frequently asked questions

What income year determines my 2027 IRMAA?

Your 2025 federal tax return. Medicare uses a two-year lookback: the Social Security Administration receives modified adjusted gross income from the IRS for the most recent year available, which for 2027 premiums is tax year 2025. Nothing you do with your income in 2026 or 2027 changes your 2027 IRMAA; it affects 2028 and 2029.

What are the projected 2027 IRMAA thresholds?

The first four thresholds are indexed each year to the change in the Consumer Price Index and rounded to the nearest $1,000. Applying roughly 3 percent inflation to the 2026 thresholds of $109,000 single and $218,000 joint produces projected 2027 first-tier thresholds of about $112,000 and $225,000. The top tier, $500,000 single and $750,000 joint, is fixed by statute and does not move until 2028. CMS publishes the final 2027 figures in November 2026.

How much is the 2027 Medicare Part B premium expected to be?

The 2025 Medicare Trustees Report projected a standard 2027 Part B premium of about $218.60 a month, up from $202.90 in 2026. IRMAA tiers are set as multiples of the standard premium: 140 percent, 200 percent, 260 percent, 320 percent, and 340 percent. On the projected base, that produces total Part B premiums of roughly $306, $437, $568, $700, and $743 a month in the five surcharge tiers. CMS sets the actual figure in the fall.

Why does IRMAA hit federal retirees so often?

Because nearly everything a federal retiree receives counts toward modified adjusted gross income: the FERS or CSRS annuity, Social Security (the taxable portion), traditional TSP withdrawals and required minimum distributions, Roth conversions in the year they are made, and tax-exempt interest, which is added back. A GS-13 couple with two pensions, two Social Security checks, and RMDs can cross the first joint threshold without any unusual income. FEHB premiums and VA disability compensation do not count.

Can I appeal my 2027 IRMAA if my income dropped?

Yes, if the drop is caused by one of the life-changing events the Social Security Administration recognizes: retirement or reduced work hours, marriage, divorce or annulment, death of a spouse, loss of income-producing property, or loss or reduction of a pension. File Form SSA-44 with documentation and SSA will use your more recent, lower income instead. A one-time spike from a Roth conversion, a TSP lump sum, or a home sale is not a qualifying event.

Sources
  1. CMS, 2026 Medicare Parts A & B premiums and deductibles fact sheet (November 14, 2025)
  2. SSA POMS HI 01101.020, IRMAA sliding scale tables
  3. SSA, Medicare premiums: rules for higher-income beneficiaries (two-year lookback, MAGI definition)
  4. SSA, Form SSA-44, Medicare IRMAA life-changing event
  5. Social Security Act § 1839(i), income-related increase in Part B premium: tier percentages and CPI indexing of thresholds
  6. 2025 Annual Report of the Medicare Boards of Trustees (projected 2027 Part B premium)
  7. Bureau of Labor Statistics, Consumer Price Index (CPI-U), 2025–2026 releases