IRMAA and Early Retirement: The Medicare Surcharge Trap

Your Roth conversion decisions at ages 63–64 lock in your Medicare premium costs at 65. The 2-year lookback is one of the most expensive mistakes early retirees make — and one of the easiest to avoid with a little planning.

What IRMAA is

IRMAA — Income-Related Monthly Adjustment Amount — is a surcharge added to your Medicare Part B (medical) and Part D (drug) premiums when your MAGI exceeds IRS-published thresholds. The standard 2026 Part B premium is $202.90/month. Depending on your income, you can pay anywhere from $81 to $487 more per month on top of that.¹

IRMAA is a cliff structure. Cross a threshold by $1 and you owe the full surcharge for the entire year. At Tier 1 — the first surcharge tier — crossing the $109,000 MAGI threshold as a single filer costs $1,148/year in additional Medicare premiums. You don't phase into it gradually; you fall off the edge.

The 2-year lookback: why early retirees are exposed

Here's the trap: Medicare determines your 2026 IRMAA based on your 2024 MAGI — two years prior. This creates a specific danger for people who retire at 58–64 and immediately begin Roth conversions.

The lookback cuts both ways. If you retire at 62 and your income drops dramatically in your first year, your Medicare premium at 64 reflects your high-income working years — not your new, lower retirement income. You can contest this with a life-change exception (see below).

2026 IRMAA tiers

For 2026, IRMAA is based on your 2024 MAGI. Thresholds for single filers and married filing jointly differ because IRMAA is household-income-based while premiums are per-person.²

Per-person premiums. A married couple where both are on Medicare pays the surcharge twice. Part D surcharge is added on top of whatever plan premium you select. The $500K/$750K top tier is frozen until 2028.³

IRMAA Conversion Headroom Calculator

Enter your estimated base MAGI (all income except the Roth conversion you're planning) and the conversion amount. The calculator shows your resulting IRMAA tier, annual surcharge cost, and how much headroom you have — or how much to reduce the conversion to stay at a lower tier.

Why IRMAA hits single filers hardest

For single early retirees, the IRMAA Tier 1 threshold ($109,000 MAGI) creates an unusual constraint. The top of the 22% federal tax bracket is approximately $121,800 AGI (= $105,700 taxable income + $16,100 standard deduction).⁴ The IRMAA ceiling is $109,000 — $12,800 below the 22% bracket top.

This means: a single filer converting "all the way to the 22% bracket" would cross into Tier 1 IRMAA first. The standard advice to "convert up to the top of your bracket" needs a IRMAA overlay for anyone within 2 years of Medicare.

For married filers, the dynamic is different: IRMAA's $218,000 threshold falls below the 22% bracket ceiling (~$233,800 AGI), but most MFJ early retirees planning Roth conversions at $100,000–$200,000 are comfortably under both ceilings. MFJ filers have far more conversion room at the standard IRMAA tier than single filers do.

The four constraints for early retirees at ages 63–64

Early retirees in the final 2 years before Medicare face a unique multi-constraint optimization. Listed from most restrictive to least for a typical case:

1. ACA subsidy cliff ($63,840 single / $86,640 MFJ): If you're still on an ACA marketplace plan at 63–64, keeping MAGI below this threshold preserves premium tax credits worth $8,000–$15,000/year. This is the most expensive cliff and is below the IRMAA Tier 1 ceiling. If you're managing income at this level, IRMAA is not yet a concern.
2. 0% long-term capital gains window (~$65,550 AGI single): Capital gain harvesting and Roth conversions compete for this window. Use it for tax-free LTCG before layering in conversions.
3. IRMAA Tier 1 ($109,000 single / $218,000 MFJ): For anyone above the ACA cliff — whether by pension, SEPP, or deliberate choice — this is the next binding constraint for Roth conversions.
4. 22% bracket ceiling (~$121,800 AGI single): The only scenario where conversions up to this level make sense without IRMAA consequences is if you're in Medicare's Tier 1 already and the conversion math still works (or if you're doing a large one-time conversion from a RMD time bomb IRA, accepting IRMAA for a limited period).

IRMAA traps for early retirees

1. The SEPP trap

A 72(t) SEPP distribution from a $2 million IRA at the 5.00% max rate generates roughly $100,000/year in ordinary income.⁵ At $100,000, you're $9,000 below the single-filer Tier 1 ceiling — but any additional income (SS income, dividends, part-time work, capital gains) could push you over. SEPP commits you to this payment for 5 years or until 59½ — you can't dial it back once the series starts. If your total income is $105,000–$115,000 while on SEPP, you may be in Tier 1 for those years and the 2 Medicare years that follow.

2. The final-year conversion spike

Some early retirees ramp up Roth conversions aggressively in their final pre-Medicare years to minimize the traditional IRA before RMDs start at 73. A large single-year conversion (e.g., $200,000) to take advantage of lower ACA-free income is attractive on paper — but it sets 2 years of Medicare premiums in the highest tiers. If that same $200,000 had been spread over 4 years at $50,000/year, it might have stayed under Tier 1 the whole time.

3. The RMD time bomb aftermath

Early retirees who don't convert during the golden window often face RMDs at 73–75 that force $150,000–$300,000 or more in mandatory distributions. These show up as MAGI and can permanently park you in IRMAA Tier 2 or 3 for the rest of your life. The IRMAA-conscious strategy is to convert earlier — accepting modest Tier 1 surcharges for a few years to avoid decades of Tier 2–4 surcharges from unmanaged RMDs.

4. The Year 1 income spike

Many early retirees have unusually high MAGI in their first partial year of retirement: partial-year W-2 income, a severance package, or a large cap gain from selling a business. That elevated MAGI triggers IRMAA when Medicare starts 2 years later — typically exactly when you're paying full Medicare premiums for the first time. The life-change exception (below) was designed for exactly this situation.

The life-change exception: SSA Form 44

If your income dropped significantly due to a qualifying life event, you can ask SSA to use a more recent year's income rather than the 2-year lookback. The form is SSA-44, "Medicare Income-Related Monthly Adjustment Amount — Life-Changing Event."⁶

The seven qualifying life-changing events are: marriage, divorce or annulment, death of spouse, work stoppage (i.e., retirement), work reduction, loss of income-producing property, or loss of pension income. Retirement is explicitly listed — if you retired in 2024 and your 2024 MAGI is high because of partial-year W-2 wages, you can submit SSA-44 with your 2025 return to demonstrate your new, lower retirement income. SSA can then set your 2026 IRMAA based on your actual 2025 or estimated 2026 income.

Important: this is not automatic. You have to file SSA-44 and provide supporting documentation (tax returns, W-2s, or a signed statement of projected income). Do not assume SSA will adjust premiums without the form.

Planning calendar: the years that matter

Sources

1. CMS — 2026 Medicare Costs press release. Part B standard premium $202.90/mo; IRMAA surcharge ranges confirmed.
2. Kiplinger — Medicare Premiums 2026: IRMAA Brackets and Surcharges for Parts B and D. Complete 2026 tier table; $109K/$218K Tier 1 thresholds; Part D surcharges.
3. The Finance Buff — 2026–2028 Medicare IRMAA Premium MAGI Brackets. Tier 5 ($500K/$750K) frozen until 2028; year-by-year bracket projections.
4. IRS Rev. Proc. 2025-32. 2026 tax brackets and standard deductions. 22% bracket: $47,150–$100,525 TI single; std ded $16,100 single ($32,200 MFJ).
5. IRS Notice 2022-6. 72(t) SEPP rules; maximum interest rate for fixed amortization and annuitization methods (5.00% for 2026).
6. SSA Form SSA-44 — Medicare Income-Related Monthly Adjustment Amount — Life-Changing Event. Official form and instructions; 7 qualifying life events; documentation requirements.

IRMAA thresholds are adjusted annually for inflation (except the top tier). All figures are for 2026 coverage year, based on 2024 MAGI, as published by CMS and SSA. Verify current-year thresholds at SSA.gov or Medicare.gov. Values verified July 2026.