Medicare IRMAA 2026: Income Thresholds, Surcharges, and the Two-Year Trap

Most people know Medicare Part B has a monthly premium. Fewer realize that premium can more than triple for retirees with higher incomes — and that the income being measured isn't what you're earning now. It's what you earned two years ago.

That gap is where IRMAA — the Income-Related Monthly Adjustment Amount — catches people off guard. A Roth conversion to fill your tax bracket, a profitable home sale, a severance package: any of these can push your 2026 Medicare costs up by thousands, with no warning until a letter arrives from Social Security months later. The 2026 IRMAA thresholds are final, and the 2024 income year that determines them has already closed.

The 2026 IRMAA bracket table

The standard Medicare Part B premium for 2026 is $202.90 per month per person. Above certain MAGI thresholds, Social Security adds a surcharge — applied separately to each Medicare enrollee in your household.

2026 IRMAA brackets — Part B premium per person per month (based on 2024 MAGI)

2024 MAGI — single	2024 MAGI — married filing jointly	Part B surcharge	Total monthly premium
≤ $109,000	≤ $218,000	—	$202.90
$109,001 – $137,000	$218,001 – $274,000	+$81.20	$284.10
$137,001 – $171,000	$274,001 – $342,000	+$202.90	$405.80
$171,001 – $205,000	$342,001 – $410,000	+$324.60	$527.50
$205,001 – $499,999	$410,001 – $749,999	+$446.30	$649.20
$500,000 +	$750,000 +	+$487.00	$689.90

Source: CMS, effective January 1, 2026.

IRMAA also adds a separate surcharge to Part D drug plan premiums, ranging from $14.50 to $91.00 per month across the same five income tiers.

Two things make these numbers sting more than they appear. First, the surcharges apply to each enrollee — so a married couple at Tier 2 pays $405.80 × 2 = $811.60/month for Part B, vs. the $405.80 combined total they'd pay at standard rates. Second, the structure is a cliff, not a ramp. Crossing a threshold by a single dollar applies the full surcharge for that bracket — not just the excess.

Why 2024 income is what matters

The IRS reports income data to Social Security with roughly a two-year lag. Social Security sets your Medicare premiums using the most recent tax return on file. For 2026 premiums, that's your 2024 return, filed in early 2025.

This means someone who retired in January 2025 and now lives on $50,000 a year can still be paying Tier 2 or Tier 3 IRMAA in 2026 — because their 2024 income included a full year of salary. The lookback doesn't care that their current situation is different. It cares what the return said.

The lookback also determines which IRMAA tier applies when someone does a large Roth conversion or sells appreciated assets at the start of retirement. If that event happened in 2024, the bill arrived in January 2026.

What one big conversion can cost

Consider a hypothetical couple — call them the Garcias — both 66, both on Medicare in 2026. They retired in January 2024 and converted $220,000 from their traditional IRAs to Roth in that first year, filling their 24% bracket and reducing their future RMD burden. Between the conversion, Social Security benefits, and investment income, their 2024 MAGI came to $295,000.

That put them at the MFJ Tier 2 threshold ($274,001–$342,000). Their 2026 Part B premiums:

• Each person: $405.80/month
• Combined: $811.60/month
• vs. standard rate: $405.80/month combined (at ≤$218,000 MAGI)
• Extra annual cost: $4,870 in Part B alone, before Part D surcharges

Had the Garcias spread the same conversion over two calendar years — $110,000 in 2024 and $110,000 in 2025 — they could have kept their 2024 MAGI near $185,000 (below the $218,000 MFJ Tier 1 floor) and paid standard Part B premiums in 2026. Same tax work, same conversion total, same eventual Roth balance. The only difference is sequencing.

The Roth conversion calculus doesn't change — moving money from traditional to Roth is often still the right call — but the timing across IRMAA lookback years matters a lot. Filling up to $217,000 in MAGI (for a couple) instead of $274,000 can preserve standard Medicare rates for two years while still doing meaningful conversion work.

Four tactics for managing IRMAA exposure

1. Know your lookback year before you act. The surcharges for a given year are set by income from two years prior. If you're converting in 2026, you're managing your 2028 IRMAA. Think in pairs.

2. Target specific bracket floors, not just tax brackets. Tax bracket thresholds and IRMAA thresholds don't align. You can be in the 22% federal bracket and still below Tier 1 IRMAA. Conversely, filling the 24% bracket often means crossing into Tier 2 or Tier 3. Running the IRMAA brackets alongside your federal marginal rate is a separate calculation. The Roth conversion calculator models both; the marginal federal rate is not the only number that matters.

3. Qualified Charitable Distributions reduce MAGI directly. If you're 70½ or older and charitably inclined, QCDs transfer up to $111,000 (2026, indexed annually) directly from an IRA to charity — the amount never appears in gross income at all, reducing MAGI dollar-for-dollar. This is one of the few tools that reduces MAGI without reducing actual wealth.

4. Harvest capital losses strategically. Taxable accounts with embedded losses can offset gains in years when you're selling to fund retirement or rebalancing. A realized $30,000 loss against an otherwise IRMAA-triggering gain year can keep MAGI below a threshold entirely.

If you're already in the trap: SSA-44

If your 2026 IRMAA is based on income that no longer reflects your situation — you retired, lost a spouse, got divorced, or lost a job — you can appeal using Form SSA-44 (available at SSA.gov). It lets you report a "life-changing event" and request that Social Security use a more recent tax year or a current-year income estimate.

Qualifying events include retirement or reduction in work hours, marriage, divorce or legal separation, death of a spouse, loss of pension income, and employer settlement payments. The appeal is not automatic — you file, provide documentation, and wait for a determination — but for someone who went from $300,000 in earned income to $80,000 in Social Security and withdrawals, the savings can be significant.

IRMAA and your retirement income model

The IRMAA thresholds are part of why retirement income planning can't be done bracket-by-bracket in isolation. A conversion that looks efficient in terms of federal tax rate can simultaneously trigger Medicare surcharges that cut the efficiency in half — or change the math entirely for someone whose 2-year lookback year coincides with a high-income event.

The retirement income calculator at Granary projects federal taxes, Roth conversion strategies, Social Security timing, and RMD trajectories together. Running those decisions simultaneously is the only way to avoid optimizing one lever while inadvertently pulling another in the wrong direction.

If you're in the five to ten years before Medicare eligibility, modeling your retirement date now gives you enough runway to sequence income events with IRMAA years in mind, rather than discovering the interaction after the lookback window has closed.

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This post is planning education, not tax or legal advice. IRMAA determinations, appeal eligibility, and interaction with individual tax situations are best reviewed with a fee-only advisor or CPA familiar with your full income picture.