Retirees who turn 73 and skip their first required minimum distribution before year-end face a tax trap: two full RMDs stacked into a single calendar year. The IRS allows a one-time delay on that initial withdrawal, pushing the deadline to April 1 of the following year. But the second year’s distribution is still due by December 31 of that same year, creating a double hit of taxable income that can bump filers into a higher bracket or trigger larger Medicare premium surcharges.
How the April 1 delay doubles taxable retirement income
The mechanics are straightforward but easy to overlook. A person reaching age 73 must take a first RMD for that year. The IRS grants a grace period: that first withdrawal can be postponed until April 1 of the next calendar year. After that initial distribution, every subsequent RMD must be completed by December 31. So anyone who uses the April 1 extension will owe two separate distributions in the same tax year, one for the prior year and one for the current year, both counted as ordinary income on that year’s return.
The IRS 401(k) Resource Guide spells this out directly: if no distribution is made in the starting year, required distributions for two years must be made in the next year. That language applies to traditional IRAs, 401(k) plans, 403(b) accounts, and other defined-contribution arrangements, with limited exceptions for workers who are still employed and do not own 5% or more of the sponsoring company.
The one-time deferral does offer a short-term benefit: an extra few months of tax-deferred growth. But the tradeoff is concentration risk on the tax side. Two distributions landing in a single year can easily push adjusted gross income past bracket thresholds, phaseout limits for deductions, and the income tiers that determine Medicare Part B and Part D premiums. For someone whose combined RMDs total six figures, the marginal rate increase from bunching can erase whatever growth the deferral produced.
SECURE 2.0 and the age-73 threshold behind the deadline
The current age trigger traces to SECURE 2.0, enacted as Division T of the Consolidated Appropriations Act, 2023. That law raised the required beginning age to 73 for individuals born on or after January 1, 1951, as reflected in IRS guidance and the agency’s RMD FAQs. The required beginning date itself is generally April 1 of the year following the year a person reaches that applicable age, a definition codified in Publication 590-B, which also explains how to calculate annual withdrawals.
Treasury Decision 10001 addressed the regulatory framework for these changes, and the Government Accountability Office reviewed the final rule under RIN 1545-BP82, confirming its effective dates and scope. Together, these documents establish the binding calendar that governs when the first and second RMDs come due and how plan administrators must apply the rules across different types of accounts.
The practical result is that someone born in 1953 who turned 73 in 2026 can wait until April 1, 2027, to take the first RMD. However, that same retiree must still withdraw the 2027 RMD by December 31, 2027. Both distributions are fully taxable in 2027, even though each corresponds to a different RMD year. For higher-balance savers, this can mean tens of thousands of dollars in extra income appearing on a single Form 1040.
Tax and Medicare side effects of bunching RMDs
Stacking two RMDs in one year does more than increase the tax bill. The inflated income can reduce or eliminate certain deductions and credits tied to adjusted gross income, such as medical expense deductions subject to AGI floors. It can also raise the portion of Social Security benefits that becomes taxable when combined income crosses statutory thresholds.
Medicare premiums are another pressure point. Income-related monthly adjustment amounts for Part B and Part D are based on modified adjusted gross income from two years prior. A single year with doubled-up RMDs can therefore trigger higher Medicare surcharges that show up later, effectively extending the cost of the deferral well beyond the year the distributions are taken.
For married couples, the impact can be magnified when both spouses reach RMD age within a short window. If each delays a first withdrawal, a future calendar year could contain four separate RMDs-two for prior years and two for current years-dramatically increasing joint taxable income and the likelihood of crossing multiple tax and Medicare thresholds at once.
Planning around the first RMD deadline
Because the April 1 extension is optional, retirees can choose instead to take the first RMD in the year they turn 73 and avoid bunching. Spreading withdrawals over more tax years may keep income within lower brackets and mitigate downstream effects on Medicare and Social Security taxation. Some savers also pair earlier RMDs with partial Roth conversions in low-income years to reduce future required withdrawals.
Advisers often recommend modeling both scenarios-deferring to April 1 or taking the first RMD in the initial year-before making an election. The optimal choice depends on account size, other income sources, expected future earnings, and whether large deductions or unusual expenses will offset income in a particular year. What looks like a small timing decision can materially shift lifetime tax costs.
The bottom line: the April 1 grace period is not free. It trades a modest extension of tax deferral for the risk of compressing income into a single year, with ripple effects across tax brackets, Medicare premiums, and benefit taxation. Understanding how the rules operate, and planning the first RMD accordingly, can help retirees avoid an avoidable tax shock just as they settle into retirement.
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