In this guide
Step one: which rule applies to you
Almost every wrong inherited-IRA RMD starts the same way: the beneficiary reaches for a calculator before establishing which regime they're in. Learning how to calculate the RMD for an inherited IRA is really two questions, and the second one is trivial once the first is settled.
Your regime is fixed at the owner's death by exactly two facts: your relationship to the owner, and whether the owner had reached their required beginning date (RBD). The RBD is generally April 1 of the year after the owner turned 73 — 72 for owners who reached 72 before 2023, and 70½ under the older rules. As a rule of thumb: died at 74 or older means yes, died at 72 or younger means no, and 73 is the ambiguous year you should confirm from the owner's last Form 1099-R.
| You are… | Owner died… | Annual RMD? | Account empty by | Factor method |
|---|---|---|---|---|
| Surviving spouse who treats the IRA as their own | Either | No — your own RMDs begin at 73 | Never | Uniform Lifetime Table |
| Surviving spouse who keeps it titled as inherited | Either | Yes, over your own life expectancy | Never | Single Life, re-read every year |
| Minor child of the owner | Either | Yes | Dec 31 of the year they turn 31 | Single Life, subtract-one |
| Disabled or chronically ill individual | Either | Yes | Never | Single Life, subtract-one |
| Not more than 10 years younger than the owner | Either | Yes | Never | Single Life, subtract-one |
| Any other individual — most adult children | On or after RBD | Yes, in years 1–9 | Dec 31 of the 10th year after death | Single Life, subtract-one |
| Any other individual — most adult children | Before RBD | No | Dec 31 of the 10th year after death | None — deadline only |
| Any non-EDB of an inherited Roth IRA | Always treated as before RBD | No | Dec 31 of the 10th year after death | None — deadline only |
| Anyone who inherited before 2020 | — | Yes | No deadline | Pre-SECURE stretch, subtract-one |
The first five rows are the eligible designated beneficiaries — the only people who kept the old stretch when the SECURE Act rewrote the rules for deaths after 2019. Everyone else who is an individual falls into the sixth and seventh rows, and that group is by far the largest. Note what a Roth inheritance does: because a Roth IRA has no lifetime RMDs, its owner is always treated as having died before the required beginning date, so an inherited Roth under the 10-year rule never carries an annual requirement.
Want the answer rather than the framework? The inherited IRA RMD calculator asks five questions — account type, your relationship, year of death, whether the owner had reached their RBD, and your birth year — and returns your regime, your deadline, this year's dollar figure, and the full year-by-year schedule.
The 10-year rule, precisely
The inherited IRA 10-year rule says the entire account must be gone by December 31 of the year containing the tenth anniversary of the owner's death. A 2024 death means a December 31, 2034 deadline. That part was never in dispute.
What was in dispute — for four years, through two rounds of proposed regulations — is whether anything is required inside the window. The July 2024 final regulations settled it on the "at least as rapidly" principle: if distributions had already begun during the owner's lifetime, they cannot stop.
- Owner died on or after their RBD → an annual RMD in each of years one through nine, on the Single Life Table, plus emptying the account in year ten.
- Owner died before their RBD → no annual RMDs at all. One deadline, ten years out, total freedom about timing in between.
The enforcement history matters right now. While the regulations were pending, the IRS waived the excise tax on annual RMDs missed under the 10-year rule for 2021, 2022, 2023 and 2024. That relief has expired. Annual RMDs under the 10-year rule are enforced beginning with the 2025 distribution year — which means a beneficiary who has been sitting still since 2021 has real 2025 and 2026 exposure, but no back-year liability for the waived years. The waived amounts are also not "made up"; each year's requirement stands on its own.
A no-annual-RMD window is a trap as often as a gift. Ten years of nothing followed by one enormous year-ten withdrawal is the most expensive way to empty an inherited IRA — it stacks a decade of deferred income into a single bracket, and often into a single IRMAA tier. Nothing forces you to spread it. Spread it anyway.
The arithmetic: one balance, one factor
Once you know you owe something, the calculation never changes:
RMD = prior year's December 31 balance ÷ your life expectancy factor
Two details carry all the errors. First, it is last year's closing balance, not today's — your 2026 RMD divides the December 31, 2025 statement value, no matter what markets have done since. Second, the factor comes from the Single Life Table, Table I in IRS Publication 590-B, on the mortality basis that took effect for 2022 and later distribution years.
Do not reach for the Uniform Lifetime Table (Table III). That is what account owners use for their own RMDs, and its factors are much larger — 26.5 at age 73 against the Single Life Table's 16.4. Using the owner's table on a beneficiary account understates the required amount by roughly 40%, and it is the single most common inherited-IRA mistake we see.
Then the part people genuinely don't expect: you look your factor up once. Use your age on your birthday in the year after the owner's death — the first year a distribution can be required — and from then on subtract exactly 1.0 for every subsequent year. You never return to the table. That is the subtract-one method, and it is why the required percentage climbs every single year: the numerator is a real balance that may grow, but the denominator shrinks by a full year annually.
One mechanical edge case: if subtract-one grinds your factor down to 1.0 or below, the remaining balance must come out in full that year. For an older beneficiary on a long stretch, that moment can arrive before any 10-year deadline would have.
A worked example, year by year
David was born in 1975. His mother died in 2024 at age 80, well past her required beginning date, leaving him a traditional IRA. He is not disabled, not a minor, and more than 10 years younger than she was — so he is in row six of the table above: the 10-year rule, with annual RMDs. His deadline is December 31, 2034.
- Find the first distribution year. The year after the death: 2025.
- Find your age in that year. David turns 50 in 2025.
- Look up the factor, once. Table I gives 36.2 at age 50. That is his 2025 factor and the only lookup he will ever do.
- Subtract one per year after that. 2026 → 35.2. 2027 → 34.2. 2028 → 33.2, and so on.
- Divide the prior year-end balance. The account held $500,000 on December 31, 2025, so his 2026 RMD is $500,000 ÷ 35.2 = $14,205.
| Year | David's age | Factor | Required % | RMD on a flat $500,000 |
|---|---|---|---|---|
| 2025 — first year | 50 | 36.2 | 2.76% | $13,812 |
| 2026 | 51 | 35.2 | 2.84% | $14,205 |
| 2027 | 52 | 34.2 | 2.92% | $14,620 |
| 2030 | 55 | 31.2 | 3.21% | $16,026 |
| 2033 — year 9 | 58 | 28.2 | 3.55% | $17,730 |
| 2034 — year 10 | 59 | — | 100% | Empty the account |
The lesson is in the last row. Nine years of minimums pull out roughly 3% a year while the balance keeps compounding — and then year ten demands everything that's left, in one tax year, at David's peak earning age. The annual RMD is a floor, not a plan. Illustrative only: the table holds the balance flat at $500,000 so you can see the factor's effect cleanly, and your real RMD each year divides that year's actual prior-December-31 value.
Spouses: the one beneficiary who re-reads the table
A surviving spouse who is the sole beneficiary has an option nobody else gets: treat the IRA as their own, or roll it into their own IRA. That ends the inherited-account rules entirely — the 10-year clock disappears, nothing is required until the spouse's own RMD age of 73, and distributions then run on the gentler Uniform Lifetime Table. It usually wins. The main reason to keep the account titled as inherited is a spouse under 59½ who needs penalty-free access to the money.
A spouse who does keep it as an inherited IRA gets a second concession, and it is the one exception to everything in the section above: they do not subtract one. A surviving spouse re-reads Table I fresh every year, using their age that year. Because the table's life expectancy declines by less than a full year for each year of age, annual recalculation leaves a persistently larger factor — and therefore smaller required distributions — than subtract-one would. Over a long widowhood that difference compounds meaningfully.
There is one more spousal timing rule worth knowing: if the owner died before their required beginning date, a sole-beneficiary spouse may delay the first distribution until the year the owner would have reached age 73.
The year-of-death RMD isn't yours
A separate obligation that catches almost everyone in the first twelve months: if the owner had reached their required beginning date and died without having taken their full RMD for the year they died, that shortfall still has to come out of the account.
It is not your RMD. It is the owner's — computed on the owner's age and the Uniform Lifetime Table, not on your Single Life factor — and your own schedule doesn't begin until the following year. The distribution lands on the beneficiary's tax return, and where there are several beneficiaries they can satisfy it in any proportion among themselves. The 2024 final regulations added a welcome piece of mercy here: beneficiaries generally have until December 31 of the year after the death to clear a year-of-death shortfall under an automatic waiver of the excise tax, rather than scrambling in the weeks after a funeral.
What a missed RMD costs
The excise tax on an amount you should have withdrawn and didn't is 25% of the shortfall — reduced to 10% if you correct it within the two-year correction window. SECURE 2.0 cut it from the old 50%, which is real relief, but 25% of a missed distribution is still a punishing number.
You report it on Form 5329, and the IRS can waive it entirely where the shortfall was due to reasonable error and you are taking steps to fix it — attach a short statement, take the missed amount immediately, and ask. The IRS RMD FAQs set out the mechanics. Two things to remember: custodians calculate owner RMDs but are not required to calculate beneficiary RMDs, and the IRS holds you responsible for the amount either way.
Planning inside the window
Knowing the required number is the easy half. What it costs you is the rest of the decision, and a 10-year window compresses decades of deferred income into one decade of your brackets.
- Level the drawdown rather than defer it. Dividing the balance by the years remaining and taking that much annually usually beats both the bare minimum and the year-ten lump, because it fills the same brackets repeatedly instead of blowing through them once.
- Watch the cliffs, not just the brackets. Inherited-IRA distributions raise MAGI, so they can trip an IRMAA tier, extra Social Security taxation, or the 3.8% NIIT two years downstream. Those are thresholds, not slopes — a dollar over costs the whole step.
- Sequence around low-income years. A sabbatical, a business loss, the gap between retiring and claiming Social Security — take more from the inherited account in those years and less in peak ones. The RMD tax guide ranks the levers that genuinely move the bill against the ones that only look like they do.
- If you're 70½ or older, use QCDs. A qualified charitable distribution from an inherited IRA satisfies that account's RMD dollar-for-dollar while staying out of your income entirely — up to $111,000 in 2026. Your age is what qualifies you; the owner's is irrelevant.
- Don't convert it — you can't. A non-spouse beneficiary cannot convert an inherited IRA to a Roth. What you can do is convert your own accounts in the years the inherited distributions are smallest; the Roth conversion calculator prices that trade-off across a full retirement.
Run your own figures first: the inherited IRA RMD calculator gives you the regime, the deadline and the year-by-year schedule in one screen, and the rest of the calculator suite prices what those distributions do to your tax bill, your Medicare premiums and your conversion room. Then confirm the number with your CPA or custodian before you withdraw — the IRS holds the beneficiary responsible for getting it right.