Your First Required IRA Withdrawal at 73 Can Push You Past the IRMAA Cliff for a Full Year

A retiree who turns 73 this year faces a deceptively simple decision: take the first required minimum distribution by December 31, or use the one-time option to delay it until April 1 of the following year. The delay can look harmless. In practice, it may dump two RMDs into a single tax year, drive modified adjusted gross income across an IRMAA bracket, and raise Medicare premiums two full years later.

Only about 8% of Medicare beneficiaries with Part B pay any IRMAA surcharge at all. The risk falls most heavily on retirees whose household MAGI sits near the 2026 thresholds: $218,000 for joint filers or $109,000 for single filers. When a first RMD stacks on top of Social Security, pension income, and taxable interest, a single calendar-year timing call can add thousands of dollars in Medicare premiums.

The two-year lookback is the trap

IRMAA draws on MAGI from two years prior. Your 2026 tax return will generally drive your 2028 Part B and Part D premiums. An RMD taken this year, based on the December 31, 2025 account balance, can therefore shape the Medicare bill you receive 24 months from now. For a voluntary distribution, there is typically no appeal route simply because income falls in a later year.

MAGI for this purpose is AGI (Form 1040 line 11) plus tax-exempt interest (line 2a). Municipal bond income that feels tax-free still counts toward the threshold. Many retirees miss this detail and land a bracket higher than they modeled.

What each bracket actually costs in 2026

The table below shows the 2026 CMS figures for the four IRMAA tiers most likely to be affected by a first-RMD timing decision. Amounts are monthly and per person: total Part B premium, plus the Part D IRMAA add-on that stacks on top of any separate drug plan premium.

Move a joint filer from the standard tier to the first surcharge tier and each spouse pays an extra $81.20 for Part B and $14.50 for Part D every month. For the couple, that translates to $2,296.80 a year in added surcharges. Cross into the second tier and the added annual cost versus the standard tier reaches $5,769.60 for the household. These are cliff thresholds: crossing by one dollar triggers the full surcharge for the entire year.

Why the first RMD is the classic trigger

The temptation is to defer the first RMD to April 1 of the following year. Do that and two RMDs land in the same tax year: the deferred first distribution and the mandatory second one. A retiree with a $900,000 traditional IRA who defers could add roughly $70,000 of taxable income in a single year, depending on the next year’s account balance. That kind of income spike can push joint MAGI past $218,000 or $274,000 in one move.

Taking the first RMD in the year you turn 73 instead spreads income across two calendar years, keeping MAGI lower in each. Under current law, the starting age is 73 for people born in 1951 through 1959 and 75 for those born in 1960 or later.

The OBBBA backdrop: why planning matters more now

The One Big Beautiful Bill Act, signed into law on July 4, 2025, did not change RMD ages or IRMAA rules. It did, however, reshape the tax environment around them in ways that affect IRMAA planning. The law made the individual income tax brackets from the 2017 Tax Cuts and Jobs Act permanent, removing the uncertainty about a bracket reset that had driven many pre-IRMAA planning conversations. It also introduced a temporary $6,000 income tax deduction for individuals age 65 and older for tax years 2025 through 2028, though that deduction phases out for single filers above $75,000 in income and for joint filers above $150,000. That phase-out ceiling puts many RMD-affected households well above the range where the senior deduction provides meaningful relief. Separately, OBBBA restricted the charitable income tax deduction for itemizers starting in 2026, which makes QCDs comparatively more valuable for retirees who give to charity.

The survivor trap most couples never model

When one spouse dies, the survivor will eventually file as single. The single IRMAA brackets are roughly half the joint ones. A household that comfortably sat below $218,000 as a married couple can leave the surviving spouse close to, or above, the $109,000 single threshold with the same portfolio and RMD structure intact. Death of a spouse qualifies as a life-changing event under the SSA-44 process, but the lower single thresholds continue to apply after that transition is complete.

SSA-44 will not save a voluntary RMD

Form SSA-44 lets the Social Security Administration reconsider IRMAA after a qualifying life-changing event: marriage, divorce or annulment, death of a spouse, work stoppage, work reduction, certain losses of income-producing property, loss of pension income, or an employer settlement payment. A large RMD, Roth conversion, or voluntary home sale does not qualify on its own. If you voluntarily raise MAGI, the surcharge almost always stands.

What to do

• Take the first RMD in the calendar year you turn 73, not during the April 1 grace period, unless a tax professional has run the two-year IRMAA math and confirmed the deferral wins in your specific situation.

• If you are charitably inclined and at least 70½, direct distributions from your IRA to a qualified charity as a qualified charitable distribution. For 2026, the QCD limit is $111,000 per person, or up to $222,000 for a married couple when each spouse has an eligible IRA. QCDs count toward an RMD without adding to AGI, making them one of the most effective IRMAA defenses in the tax code. Unlike ordinary charitable deductions, a QCD is an income exclusion rather than a deduction, so it lowers MAGI whether or not you itemize.

• If your projected joint MAGI is within $20,000 of a threshold, ask a fee-only advisor to model withdrawal timing, capital gains, QCDs, and taxable interest before December 31.

Plan the RMD before Medicare prices it

The first RMD decision is not only a tax deadline. It is also a Medicare premium decision that surfaces two years later. Deferring until April 1 can work well in the right tax year, but retirees near an IRMAA threshold should treat that grace period as a deliberate planning tool rather than a default. The cost of getting the timing wrong shows up quietly, in a Social Security check deduction two years after the fact, with little recourse once the income is on the books.

Sources: 2026 Medicare premium and IRMAA figures come from the CMS “2026 Medicare Parts A & B Premiums and Deductibles” fact sheet. RMD timing and first-year deferral rules come from IRS RMD guidance. SSA-44 qualifying events come from Social Security Administration Form SSA-44. The 2026 QCD limit comes from IRS Notice 2025-67. OBBBA provisions, including the senior deduction and its phase-out thresholds, come from the One Big Beautiful Bill Act signed July 4, 2025.

Editor’s note: This update adds context on the One Big Beautiful Bill Act (signed July 4, 2025), noting that while it did not change RMD ages or IRMAA rules, it made TCJA tax brackets permanent, introduced a temporary $6,000 senior deduction (2025-2028) that phases out well below most IRMAA-affected income levels, and restricted itemized charitable deductions in ways that make QCDs more valuable. The QCD couples limit of $222,000 (when both spouses hold eligible IRAs) was also added, sourced from Fidelity and the Congressional Research Service.

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