Missed RMD Penalty Calculator

Failing to take a Required Minimum Distribution (RMD) from a Traditional IRA, 401(k), or inherited Roth triggers an excise tax under IRC §4974 on the shortfall: 25 % of the missed amount, reduced to 10 % if corrected within two years per SECURE 2.0 §302. (Before 2023 the rate was 50 %, one of the harshest penalties in the Code.) This tool computes the exact penalty for your situation and walks through the Form 5329 waiver-request process, which the IRS grants routinely if you can document "reasonable cause" for the miss.

The penalty sounds frightening, and the math can be. But three facts change the picture. First, the rate dropped from 50 % to 25 % in 2023 and to 10 % with prompt self-correction. Second, the IRS has discretion under §4974(d) to waive the tax entirely when the failure is due to "reasonable error" and "reasonable steps are being taken" to remedy it. Third, historical IRS practice has been to grant the waiver in the vast majority of filed cases where the taxpayer demonstrates good faith. The tool walks you through producing exactly the documentation that triggers that practice.

Who should use this tool

Anyone who missed an RMD for any reason — a late first-year RMD, a missed RMD on an inherited account, a miscalculated amount that fell short, or a year where life events simply caused the deadline to slip. Also beneficiaries of inherited accounts still figuring out the post-SECURE rules — missing an inherited-account RMD is surprisingly common because the mechanics aren't intuitive and the forms don't always prompt for it.

It's also useful before a miss happens: running the tool once shows you how much a miss would cost and drives home the incentive to set calendar reminders for future years. For many retirees, automating the RMD with the custodian is the cleanest fix — most custodians offer "automatic RMD" programs that compute and distribute the correct amount on December 15 every year.

Walking through the inputs

Required RMD amount. The amount you should have taken. For a Traditional IRA, this is the prior-year-end balance divided by the Uniform Lifetime Table factor for your age. For an inherited account subject to life-expectancy RMDs (Eligible Designated Beneficiaries), use the Single Life Table factor. If you're not sure which table applies, the tool has a separate flow for computing the right amount from your balance and age.

Amount actually taken. Can be zero. Partial distributions still count — the penalty applies only to the shortfall, not the full RMD.

Year of the missed RMD. Affects which excise-tax rate applies (50 % before 2023, 25 % from 2023, 10 % if corrected within two years per SECURE 2.0 §302). Pre-2023 misses are rarely the right thing to calculate because they're outside the statute of limitations in most cases, but the tool handles them if you need to.

Whether you've taken the "make-up" distribution. Taking the shortfall as soon as you discover the miss is the first step to a waiver and to the reduced 10 % rate. The tool will tell you this explicitly in the output.

Reasonable-cause facts. A text field where you describe the circumstances of the miss — serious illness, death in the family, custodian error, reliance on incorrect professional advice. The tool uses your input to draft a reasonable-cause statement.

How to read the result

The tool shows four things. The excise tax owed — 25 % or 10 % of the shortfall, depending on timing. The make-up distribution still needed — take it immediately, before filing Form 5329, to qualify for the reduced rate. A draft reasonable-cause statement you can attach to Form 5329 — edit for your specific facts, but the structure matches what the IRS is looking for. The post-waiver outcome — if the waiver is granted (which the IRS does in the large majority of documented cases), the tax is zero and you only owe ordinary income tax on the distribution itself.

The tool also generates a "prevention checklist" for future years: set up automatic RMDs with your custodian, calendar the December 1 check, and use a spreadsheet to consolidate RMDs across multiple accounts.

Common mistakes this tool prevents

• Assuming the 25 % rate still applies after self-correcting. SECURE 2.0 §302 dropped the rate to 10 % for taxpayers who correct within two years, and the IRS often waives the 10 % too. The default assumption should be that a good-faith correction with documented cause pays nothing — but only if you actually file the waiver request.
• Missing the first-year grace period. Your first RMD can be deferred to April 1 of the following year without penalty. But if you defer, you must take two RMDs in that following year, which often pushes you into a higher bracket. Running the numbers on "take year 1 by December 31 versus defer to April 1 of year 2" is usually worth doing.
• Forgetting about inherited accounts. Inherited-account RMDs are computed differently and cannot be aggregated with your own IRA RMDs. If you have both your own IRAs and an inherited IRA, you must take each separately. Most RMD-miss cases the IRS sees involve inherited accounts for this reason.
• Not filing Form 5329. The form is how you report the missed RMD and request the waiver. Without it, the IRS can assess the full penalty on audit, and the assessment may be final. File Form 5329 with the draft reasonable-cause statement even if you're not sure a waiver is required — the downside is small and the upside is full protection.
• Confusing the RMD start age. SECURE 2.0 §107 raised the start age to 73 for most retirees and to 75 for those born in 1960 or later. Miscalculating the start year is a very common cause of "missed" RMDs that weren't actually required yet.
• Double-counting across accounts. You can aggregate RMDs across multiple Traditional IRAs and take the total from any one of them. You cannot aggregate IRA RMDs with 401(k) RMDs — each 401(k) must distribute its own RMD.

After you compute the penalty

Take the make-up distribution immediately, even before filing Form 5329. This both qualifies you for the reduced 10 % rate and establishes the "steps being taken" element of the waiver request. Document the cause of the miss in writing and attach the statement to Form 5329. Ninety-plus percent of reasonable-cause waiver requests are granted for first-time misses with documented facts.

For future prevention, the simplest fix is to set up the custodian's automatic-RMD program, which computes and distributes the correct amount each year without manual action. The RMD rules pillar covers aggregation, the UL and SL tables, and each of the enumerated exceptions.