Deferring a First RMD to April 1 Postpones the Tax and Enlarges the Second

A traditional IRA owner born in 1953 reaches age 73 during 2026, and from that point two different deadlines govern the same account. The first required minimum distribution can be postponed until April 1 of the following year. Every distribution after that one is due by December 31. The postponement is usually described as a way to push income into a later year, and it does that. It also does something the tables do not show: it makes the second distribution larger, and it lands both distributions in the same tax year.

The Internal Revenue Service publishes the divisor. It does not publish what that divisor works out to as a share of the account, and it does not publish what the deferral costs. Both are computed below from the published numbers.

The two deadlines the rules set

The IRS states the first-year rule directly in its required minimum distribution FAQs: "You must take your first required minimum distribution for the year in which you reach age 73. However, you can delay taking the first RMD until April 1 of the following year." The same page shows the consequence in its own example: "If you reach age 73 in 2024, you must take your first RMD by April 1, 2025, and the second RMD by Dec. 31, 2025."

Two distributions, one calendar year. That is the structure of the deferral, not a quirk of the example.

Which birth years reach the threshold is set by statute and by the final regulations Treasury and the IRS published on July 19, 2024. The preamble to those regulations states that "for employees born on or after January 1, 1951, but before January 1, 1959, the applicable age is 73" and that "for employees born on or after January 1, 1960, the applicable age is 75." That pair leaves 1959 unaddressed. A proposed regulation issued the same day, REG-103529-23, explains that employees born in 1959 "are described in section 401(a)(9)(C)(v)(I) of the Code (which provides that the applicable age for those employees is age 73) as well as section 401(a)(9)(C)(v)(II) (which provides that the applicable age for those employees is age 75)." Its regulatory text resolves the overlap one way: "In the case of an employee born in 1959, the applicable age is age 73." That resolution sits in a proposed rule rather than a final one.

For an IRA there is no employment test attached to the date. Under 26 CFR 1.408-8(b)(1), "the IRA owner's required beginning date is April 1 of the calendar year following the calendar year in which the individual attains the applicable age." Employer plans are treated differently. The IRS FAQ puts it this way: "Participants in a workplace retirement plan (for example, 401(k) or profit-sharing plan) can delay taking their RMDs until the year they retire, unless they're a 5% owner of the business sponsoring the plan."

The divisor is published. The percentage is not.

The arithmetic itself is one line. The IRS describes it as follows: "A RMD is calculated for each account by dividing the prior December 31 balance of that IRA or retirement plan account by a life expectancy factor that the IRS publishes in Tables." Table III of Appendix B to Publication 590-B, the Uniform Lifetime Table, supplies that factor for most owners. It reads 26.5 at age 73, 25.5 at 74, 24.6 at 75, 20.2 at 80, 16.0 at 85, 12.2 at 90, 8.9 at 95 and 6.4 at age 100.

Dividing 100 by each divisor converts the table into a figure the IRS does not print: the share of the prior December 31 balance that has to leave the account. At 73 that share is 3.7736 percent. It crosses 5 percent for the first time at age 81, where it reaches 5.1546 percent. It crosses 10 percent for the first time at age 94, at 10.5263 percent. By age 89 it has slightly more than doubled from the age-73 figure, and at age 100 it stands at 15.6250 percent. The curve is nearly flat for the first decade and steepens afterward, which is why the first two years look so much alike.

The one step where the table drops by a full year

Between age 72 and age 100 the Uniform Lifetime divisor falls by 0.4 to 0.9 at each step, with one exception. From 73 to 74 it falls from 26.5 to 25.5, a drop of exactly 1.0.

Assume for a moment no growth and no withdrawals beyond the required ones. If the age-73 distribution is taken during the age-73 year, the balance entering the next calculation has been reduced by a factor of 25.5 over 26.5, and dividing that smaller balance by 25.5 returns the identical dollar figure. The algebra is short: one minus one-divided-by-26.5, all divided by 25.5, equals one divided by 26.5. Two consecutive years, the same amount, and only because those two divisors are exactly one apart.

Two paths from the same December 31 balance

Take an owner born in 1953 whose traditional IRA held $500,000 on December 31, 2025. The 2026 distribution is $500,000 divided by 26.5, or $18,867.92. The required beginning date is April 1, 2027. The 2027 distribution is the December 31, 2026 balance divided by 25.5, due December 31, 2027.

Taking the 2026 amount during 2026 leaves $481,132.08 on December 31, 2026. Dividing that by 25.5 gives $18,867.92 again. Deferring instead leaves $500,000 on December 31, 2026, because nothing was withdrawn, so the 2027 distribution becomes $500,000 divided by 25.5, or $19,607.84. Both distributions then fall in 2027: $18,867.92 by April 1 and $19,607.84 by December 31, for $38,475.76 in a single tax year.

The gap between the two second-year figures is $739.92. As a share of the December 31, 2025 balance that is 0.1480 percent, the difference between 1 divided by 25.5 and 1 divided by 26.5. The percentage is fixed, so the dollars scale: on a $1,200,000 balance the same deferral produces a second-year distribution $1,775.80 larger. And the stacked year moves 7.6951 percent of the original balance, the two shares added together, into one return.

Why the deferred year comes out larger

The reason is the valuation date, not the calendar. Publication 590-B is explicit about which distributions count: "A distribution for last year made after December 31 of last year reduces the account balance for this year, but not for last year. Disregard distributions made after December 31 of last year in determining your required minimum distribution for this year."

The regulation says the same thing in colder language. Under 26 CFR 1.408-8(b)(2), the December 31 balance of the preceding year is used, and "Except as provided in paragraph (d) of this section, no adjustments are made for contributions or distributions after that date." Paragraph (d) concerns rollovers and transfers, which are added back so that money in transit is not counted twice. A first distribution paid in January, February or March is not in that exception. It reduces the balance that will drive the following year's calculation, one year too late to reduce the current one.

Which balance, which table, which account

Table III is not the only table. Publication 590-B directs owners to "Use Table III if you are the IRA owner and your spouse isn't the sole designated beneficiary or if your spouse is the sole designated beneficiary of your IRA and not more than 10 years younger than you." Where the sole beneficiary is a spouse more than 10 years younger, the publication says to "use the applicable denominator from Table II," which produces a longer distribution period and therefore a smaller required amount.

Where the money may come from is a separate question. An IRA owner figures the amount for each IRA and may then withdraw the total from one account or several. Employer plans do not work that way: "However, RMDs required from other types of retirement plans, such as 401(k) and 457(b) plans, must be taken separately from each of those plan accounts." Roth accounts sit outside the requirement during the owner's lifetime, though not afterward: "The RMD rules do not apply to Roth IRAs or Designated Roth accounts while the owner is alive. However, RMD rules do apply to the beneficiaries of Roth IRA and Designated Roth accounts."

What a missed deadline costs

The penalty is a percentage of the shortfall, not of the account. The IRS states it as follows: "If an account owner fails to withdraw the full amount of the RMD by the due date, the amount not withdrawn may be subject to an excise tax of 25%, 10% if the RMD is timely corrected within two years." On the $18,867.92 figure above, a complete miss puts $4,716.98 at stake, falling to $1,886.79 if corrected inside the two-year window. The IRS adds that the owner "should file Form 5329, Additional Taxes on Qualified Plans (Including IRAs) and Other Tax-Favored Accounts, with their federal tax return for the year in which the full amount of the RMD was required, but not taken," and that "the penalty may be waived if the account owner establishes that the shortfall in distributions was due to reasonable error and that reasonable steps are being taken to remedy the shortfall."

Numbers to Re-check

Figure	Basis used here	Where to confirm	When it moves
Divisor 26.5 at age 73, 25.5 at 74	Table in effect for 2026 and 2027 distribution years	IRS Publication 590-B, Appendix B, Table III	Only when the mortality tables are re-issued by regulation
Applicable age 73	Born on or after January 1, 1951 and before January 1, 1959	Final regulations, July 19, 2024	Rises to 75 for those born on or after January 1, 1960
Applicable age for those born in 1959	Age 73 under proposed text	REG-103529-23	When the proposed rule is finalized or changed
Excise tax 25 percent, 10 percent if corrected	Rules as stated in the 2026 IRS FAQs	IRS required minimum distribution FAQs; Form 5329	By statute only
Account balance rule	Prior December 31, rollovers excepted	26 CFR 1.408-8(b)(2) and (d)	By regulation only

Where This Doesn't Apply

The paired figures above assume a flat balance. Real accounts move. If the account gains between January and December of the age-73 year, deferral is applied to a larger December 31 balance and the gap widens; if it falls, the gap narrows. The comparison isolates the divisor effect and nothing else.

The dollar comparison is also pre-tax. Stacking two distributions into one year raises that year's taxable income, and several federal calculations are keyed to income thresholds rather than to the distribution itself, so the year with two distributions can interact with those thresholds differently than two ordinary years would. A household whose marginal rate is expected to change between the two years faces different arithmetic.

Owners of employer plans who are still working may have a later required beginning date, unless they are 5 percent owners of the business sponsoring the plan. Owners whose sole beneficiary is a spouse more than 10 years younger use Table II, so the 26.5 and 25.5 divisors do not describe their accounts. Roth IRAs and designated Roth accounts carry no lifetime requirement for the owner. Inherited accounts follow the beneficiary rules, a separate regime not covered above. State income tax treatment of retirement distributions varies and is not addressed here at all.

This article explains how the rules are written. It is not tax, legal, or insurance advice, and it does not account for any individual situation. Amounts and thresholds change; verify the current figures at the source listed above before acting, and consult a qualified tax professional about a specific account.