RMD Penalty Calculator: the 25% Excise Tax on a Missed RMD, 10% if You Fix It in Time, and Form 5329

What is the penalty for missing an RMD?

An excise tax of 25% of the amount you should have withdrawn and did not, cut to 10% if you take the missing amount out within the correction window (IRC §4974, as amended by SECURE 2.0 §302). You report it in Part IX of Form 5329, and you can ask the IRS to waive it for reasonable cause (Form 5329 instructions). Example: a single 75-year-old with $400,000 in an IRA on December 31, 2025 owes a 2026 RMD of $16,260 but takes only $5,000. The shortfall of $11,260.17 carries an excise tax of $2,815.04, or $1,126.02 if corrected in time: $1,689.03 less.

The worked example: single, 75, $400,000 IRA balance on 12/31/2025, $5,000 withdrawn in 2026. RMD and excise computed by the tax engine.
Key number	2026
2026 RMD ($400,000, age 75) (Uniform Lifetime Table)	$16,260
Shortfall	$11,260.17
Excise tax at 25% (IRC §4974(a))	$2,815.04
Excise tax at 10% (corrected in the window) (IRC §4974(e))	$1,126.02
Saved by correcting in time	$1,689.03

An estimate from QuantCalc’s open tax engine (federal 2.4.0, state 1.16.4) for the 2026 tax year. Not tax advice: your return depends on facts this page does not ask about, so check a move with your tax preparer or custodian before acting. A waiver granted for reasonable cause removes the excise entirely; this page does not assume one. How the engine computes each line, with its official source: federal, state.

Your RMD penalty

RMD you had to take ($)

Amount actually withdrawn for that year ($)

I took the whole shortfall out within the correction window

Don’t know the RMD? RMD calculator, or inherited IRA RMD calculator for a beneficiary. Rates from QuantCalc’s federal tax engine (IRC §4974).

Form 5329, Part IX, line by line

Part IX of the 2025 Form 5329 splits the plans in two: the “a” lines for plans whose full shortfall you took out during the correction window, the “b” lines for all others.

Form 5329 (2025), Part IX: additional tax on excess accumulation
Line	What goes there
52a / 52b	The minimum required distribution for the year: corrected plans / all other plans
53a / 53b	The amount distributed to you during the year from those plans
54a	Line 52a minus line 53a, times 10%
54b	Line 52b minus line 53b, times 25%
55	Lines 54a + 54b; carried to Schedule 2 (Form 1040), line 8

The correction window

The 10% rate applies when you take the shortfall out before the window closes. It ends on the earliest of the date the IRS mails a notice of deficiency for the tax, the date the tax is assessed, or the last day of the second taxable year that begins after the end of the year in which the tax is imposed (Form 5329 instructions; IRC §4974(e)).

Asking for a waiver

The IRS can waive the tax if the shortfall came from reasonable error and you are taking reasonable steps to fix it. On Form 5329 you complete lines 52 and 53, enter “RC” and the amount you want waived in parentheses on the dotted line next to line 54, subtract it, finish line 55, and attach a statement of explanation (Form 5329 instructions). Take the missed amount out first: the explanation should show the remedy is underway.

Inherited accounts and the 10-year rule

A beneficiary’s missed annual RMD is taxed the same way. The IRS waived it for annual RMDs under the 10-year rule for 2021 through 2024; from 2025 it applies (IRS Notice 2024-35). The rules: inherited IRA rules 2026.

Avoid the next one

The rules on who owes what and by when: RMD rules 2026. With several accounts, a 401(k) RMD cannot be taken from an IRA (IRS RMD FAQs): which accounts can be aggregated.

Paid tool An RMD is a fraction of the traditional balance on December 31, so every dollar you move to a Roth before then is a dollar no future RMD is computed on: a Roth IRA has no RMD while you are alive (IRS RMD FAQs). The Roth Conversion Planner works out how much to convert in each year from now to your plan end age to shrink those future RMDs: the federal and state tax each conversion costs, the IRMAA tier that year’s MAGI sets two years later, and the ACA subsidy it affects — beside the same years with no conversions, and downloadable as a PDF you keep. A planning tool, not advice: the numbers move when your assumptions do. Build my conversion schedule — Personal PRO ($49) → Roth Conversion Planner: see what is included, and price this year free, first →

An RMD is ordinary income on top of everything else you have that year. QuantCalc runs your whole retirement — withdrawals, RMDs, taxes, Medicare surcharges — year by year.

Run the free tax-aware simulation →

Common questions

What is the penalty for not taking an RMD in 2026?

25% of the shortfall, or 10% if you take it within the correction window (IRC §4974). A $11,260.17 shortfall costs $2,815.04, or $1,126.02 if corrected in time.

Which Form 5329 lines report a missed RMD?

Part IX: lines 52a-54a for plans corrected within the window (10%), 52b-54b for the rest (25%), and line 55 for the total, which goes on Schedule 2 (Form 1040), line 8 (Form 5329).

How do I request a waiver of the RMD penalty?

Enter “RC” and the amount to be waived in parentheses next to line 54 of Form 5329, subtract it, and attach a statement explaining the reasonable error and the steps you are taking to fix it (Form 5329 instructions).

Is the RMD penalty still 50%?

No. Since SECURE 2.0 the IRC §4974 excise is 25% of the shortfall and 10% when corrected in time (IRC §4974); in the IRS’s words, the amount not withdrawn “may be subject to an excise tax of 25%, 10% if the RMD is timely corrected within two years” (IRS RMD FAQs).

Does the missed RMD still count as income?

Yes, when you take it: the catch-up withdrawal is taxed as income in the year it is distributed, like any IRA withdrawal (IRS Publication 590-B).

Sources

RMD rules 2026 → RMD calculator 2026 → First RMD deadline → Inherited IRA RMD calculator → Inherited IRA rules 2026 → 401(k) and 403(b) RMD aggregation → Form 1099-R explained →