The April 1 Rule, Precisely

The rule everybody half-remembers is worth stating exactly, because the halves people remember are the ones that cost money.

• Your first RMD belongs to the year you reach your start age. It is that year's distribution, computed from that year's numbers — your December 31 balance from the year before, divided by the Uniform Lifetime Table factor for your age.
• You may pay it late. The IRS allows the first distribution to be taken as late as April 1 of the following year. That date is your required beginning date.
• The allowance is one-time. Every subsequent RMD is due by December 31 of its own year. There is no April grace period for the second one, or any after it.
• Taxation follows the year you take it, not the year it is for. A first RMD paid in March counts as income in that March's tax year — which is the entire source of the trap below.

The start age itself comes from the SECURE 2.0 Act and depends only on your birth year. The RMD age calculator covers that question in full; the short version:

A footnote for the oldest savers: those born before July 1, 1949 started RMDs at age 70½ under the rules in place before the first SECURE Act. Everyone born after that date falls under the 72, 73, or 75 framework above.

The Still-Working Exception: Your Required Beginning Date May Not Be Age-Based At All

Everything above assumes your required beginning date is set by your age. For one large group of savers it is not. IRC §401(a)(9)(C)(i)(II) defines the required beginning date for an employer plan as April 1 of the calendar year following the later of the year you reach your applicable age or the calendar year in which you retire. Keep working past 73 or 75 and, for that plan, the whole first-RMD timeline slides to your retirement year.

The exception is real but narrow, and three limits do most of the damage when people miss them:

• It never applies to IRAs. §401(a)(9)(C)(i)(II) is written for qualified plans. Traditional IRAs, SEP IRAs and SIMPLE IRAs are governed by §408(a)(6) and start at your applicable age whether you are working or not.
• Only your current employer's plan. A 401(k) left behind at a former employer is not covered — those distributions begin at your applicable age.
• Not for 5% owners. §401(a)(9)(C)(ii)(I) removes the exception for anyone who is a 5-percent-or-greater owner of the business, tested for the plan year ending in the calendar year they reach the applicable age.

The plan also has to offer it: the still-working rule is permitted, not mandated, so a plan document can require distributions at the applicable age regardless. Check the summary plan description before counting on it.

Where it does apply, the double-RMD arithmetic below does not disappear — it moves. Your first distribution year becomes your retirement year, and the April 1 deferral then stacks that first RMD into the year after you retire, which is very often a low-income year you would rather keep clear. The RMD age calculator covers the exception's scope in more detail.

The Double-RMD Year Trap

Here is the whole problem in one example. Someone born in 1955 has a start age of 73 — squarely inside the 1951–1958 band the final regulation actually settles — and reaches it in 2028. Their first RMD is the 2028 distribution. They can take it during 2028, or delay it to April 1, 2029.

If they delay, 2029 contains both the delayed 2028 RMD (due April 1, 2029) and the 2029 RMD (due December 31, 2029). Two taxable distributions, one tax year. Nothing was skipped — 2028 simply has no RMD income and 2029 has double.

The damage compounds across three separate systems at once:

• Marginal bracket. Two distributions can carry the second one over a bracket edge that a single distribution would have stayed under.
• Social Security taxation. Provisional income rises with the stacked distributions, so a larger share of your benefit becomes taxable — the tax-torpedo effect.
• IRMAA, two years later. Medicare prices your Part B and Part D premiums off the tax return from two years prior. A double-RMD year in 2029 sets your 2031 premiums. IRMAA is a cliff, not a ramp: one dollar over a threshold moves the entire year's surcharge up a tier. See how RMDs trigger IRMAA surcharges and the current bracket thresholds.

Against all that, the delay buys three months of tax deferral on one distribution. That is why the default answer for most people is to take the first RMD in the year they reach start age and keep one distribution per tax year.

When the delay is actually worth taking

The delay is a real tool in two situations. First, when the start-age year is unusually high-income — a business sale, a large Roth conversion, a final year of salary — and the following year is clearly lower, moving the distribution forward can drop it into a cheaper bracket even after stacking. Second, when a partial distribution splits the income more evenly: nothing requires an all-or-nothing choice, so taking part of the first RMD in the start-age year and the rest by April 1 can flatten the two-year profile. Both cases need the actual numbers for both years, not a rule of thumb.

If You Miss the Deadline

A shortfall — taking nothing, or taking less than required — triggers an excise tax on the amount you should have withdrawn but did not, reported on IRS Form 5329.

Section 302 of the SECURE 2.0 Act of 2022 reduced that excise tax from 50% to 25% for tax years beginning after 2022. It falls further to 10% if you withdraw the missed amount and file a return reflecting the excise tax within the two-year correction window — which runs to the end of the second tax year following the year of the shortfall. A 2026 shortfall, for instance, must be distributed and reported by December 31, 2028 to qualify for the 10% rate.

That two-year figure is a maximum, not a guarantee. §4974(e)(2) defines the correction window as ending on the earliest of three events, and only the last one is the date most people have heard of:

• §4974(e)(2)(A) — the date the IRS mails a notice of deficiency for the excise tax under §6212.
• §4974(e)(2)(B) — the date the excise tax is assessed.
• §4974(e)(2)(C) — the last day of the second taxable year beginning after the end of the year the tax was imposed. This is the December 31 date above.

The practical consequence: if the IRS gets to your shortfall first, the window shuts early and the 25% rate stands. Self-correcting promptly is worth more than the calendar suggests — the two years are only yours for as long as nobody is looking.

The reduction is meaningful, but 10% of a missed distribution is still a large number on a six-figure balance, and the paperwork is unpleasant. Calendar the December 31 date, and do not treat it as a deadline you can safely run to.

Planning Around the First RMD Rather Than Reacting to It

The choice between the two years is a small optimization. The larger one sits earlier: because every RMD is a percentage of your balance, the size of the whole future stream is decided in the years before your start age. Roth conversions, qualified charitable distributions, and voluntary withdrawals in those years shrink the pre-tax base, and every future RMD with it.

That planning window closes exactly when the first deadline arrives, and it overlaps with two other clocks — the Social Security claiming decision and the Medicare enrollment window, where a missed date carries its own permanent late enrollment penalty. The years from about 62 to your start age are where those three decisions interact, and they are far easier to see together than one at a time.

When is my first RMD due?

Your first Required Minimum Distribution is for the calendar year you reach your start age, but you may delay taking it until April 1 of the FOLLOWING year. That April 1 date is called your required beginning date. It is a one-time allowance that applies only to the first distribution. Every RMD after the first is due by December 31 of its own year, with no April grace period.

What is the double-RMD year trap?

If you use the April 1 delay, two RMDs land in the same calendar year: the delayed first one by April 1, and the second one by December 31 of that same year. Both are taxable in that year. Stacking them can push you into a higher marginal bracket, raise the taxable share of your Social Security, and lift your MAGI into a higher IRMAA tier that reprices your Medicare premiums two years later. The delay buys a few months of deferral and can cost considerably more than it saves.

What age do RMDs start under SECURE 2.0?

Your start age depends on your birth year. If you were born in 1950 or earlier your RMDs began at age 72. If you were born from 1951 through 1958 your start age is 73, stated at 26 CFR 1.401(a)(9)-2(b)(2)(iv). If you were born in 1960 or later your start age is 75. Birth year 1959 is the one gap: the final regulation leaves paragraph (v) marked Reserved, and the proposed regulation REG-103529-23 assigns age 73, which is the working assumption this tool uses. Those born before July 1, 1949 started at age 70½ under the rules that preceded the SECURE Act.

What happens if I miss an RMD deadline?

A missed or short RMD triggers an excise tax on the shortfall, reported on IRS Form 5329. Section 302 of the SECURE 2.0 Act of 2022 cut that excise tax from 50% to 25% for tax years beginning after 2022. It drops further to 10% if you take the missed amount and file a return reflecting the excise tax within the correction window. That window runs at most to the end of the second tax year after the year of the shortfall, but Section 4974(e)(2) closes it earlier if the IRS mails a notice of deficiency or assesses the tax first, so the two years are not guaranteed.

Should I take my first RMD early instead of delaying to April 1?

For most people, yes. Taking the first RMD in the year you reach your start age keeps one distribution per tax year and avoids the double-RMD stack entirely. Delaying makes sense mainly when the first distribution year is unusually high-income and the following year will be clearly lower, or when a partial withdrawal splits the income more evenly across the two years. The right answer depends on your bracket, your Social Security, and your IRMAA position in both years.