Retirees who turned 73 and chose to push their first required minimum distribution to the April 1 deadline now face two taxable withdrawals landing in a single calendar year, a timing trap that can bump them into a higher federal tax bracket and inflate their Medicare premiums for the year ahead. The IRS recently flagged April 1 as the final day to begin required withdrawals from IRAs and 401(k)s in its IR-2025-33 notice, putting the stakes in sharp focus for anyone who deferred.
How the April 1 deferral stacks two RMDs into one tax year
The first required minimum distribution covers the year a retirement account owner reaches age 73, but federal rules allow that initial withdrawal to be postponed until April 1 of the following year. As the IRS explains in its guidance on required minimum distributions, this “required beginning date” can be delayed only once, and all later withdrawals must still be taken by December 31 of each year.
That flexibility comes with a cost. Because every subsequent RMD is due by December 31, a person who waits until April 1 must also take the second distribution before the same calendar year ends. Two full RMDs hit the tax return at once, even though the money may be spent or reinvested gradually over the year.
Each distribution is calculated by dividing the account balance on the prior December 31 by a life expectancy factor published by the IRS. The agency’s detailed RMD FAQs describe how these factors work across traditional IRAs and employer plans. For someone with a $500,000 traditional IRA balance, two distributions in one year can easily add tens of thousands of dollars in reportable income, enough to push a married couple from the 22 percent bracket into the 24 percent bracket or higher depending on pensions, Social Security and investment income.
The rules apply broadly across tax-deferred retirement accounts. The IRS compares the timing and calculation of withdrawals in its RMD comparison chart for IRAs and defined contribution plans, underscoring that both types of accounts can create the same double-withdrawal crunch when the first distribution is delayed to April.
This income spike can also trigger collateral tax effects. Larger RMDs may cause more Social Security benefits to become taxable, phase out certain deductions or credits, and reduce eligibility for income-based programs. For retirees who already have substantial portfolio income, the combined impact of two RMDs can be disproportionately large compared with the one-time benefit of deferring that first withdrawal by a few months.
IRMAA tier risk and the two-year income lookback
The connection between a double-RMD year and higher Medicare costs runs through a specific CMS mechanism. The agency’s 2026 fact sheet on Part B premiums confirms that premiums vary by income through IRMAA tiers, with surcharges layered on top of the standard monthly amount when modified adjusted gross income exceeds set thresholds. When two distributions land in one calendar year, the resulting income reported on that year’s tax return can cross an IRMAA boundary that would otherwise have been avoided.
Because CMS uses a two-year lookback, the surcharge appears on monthly premium bills well after the retiree has spent the withdrawal. A spike in income from RMDs on a 2024 return, for example, would generally influence Medicare premiums in 2026, leaving some retirees surprised when their Social Security checks shrink or their automatic bank drafts increase.
No publicly available IRS or CMS dataset tracks how many retirees who elect the April 1 deferral later experience an IRMAA tier increase compared with those who take the first distribution on time. The mechanical logic, however, is straightforward: anyone whose baseline income sits near an IRMAA boundary faces a measurably higher chance of crossing it when a second RMD is added to the same tax year. The effect is especially pronounced for retirees whose investment income fluctuates or who realize large capital gains in the same period.
Retirees who already chose the April 1 start date now have limited room to maneuver, but they can still blunt the impact. Some may be able to offset part of the spike with higher deductions, such as bunching charitable gifts or medical expenses in the double-RMD year. Others might coordinate with tax and financial advisers to spread additional portfolio income into different years, avoiding further bracket creep on top of the stacked withdrawals.
Looking ahead, the decision to defer the first RMD should be weighed against these downstream costs rather than viewed as a default choice. For retirees whose regular income already approaches higher tax brackets or IRMAA thresholds, taking the first distribution in the year they turn 73 can smooth taxable income over time and reduce the odds of an unpleasant surprise two years later. The short-term benefit of waiting until April may be modest, but the long-term consequences of doubling up can linger on tax returns and Medicare statements long after the deadline passes.
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