Inherited IRA 10-Year Rule: Year-by-Year RMD Math on a $500K Traditional IRA for a 45-Year-Old Heir

The setup: who has to take annual RMDs (and who doesn’t)

Short answer: if the original IRA owner had already started their own required minimum distributions before death, you — the non-spouse beneficiary — must take annual RMDs in years 1 through 9 and drain the account by December 31 of year 10. Under the IRS’s 2024 final regulations (26 CFR § 1.401(a)(9)-5), this is now settled law after four years of confusion and penalty waivers.

If the decedent died before their required beginning date (RBD) — generally April 1 of the year after turning 73 for those born 1951–1959, or 75 for those born 1960+ under SECURE 2.0 § 107 — only the year-10 deadline applies. No annual minimums in years 1–9. That’s the easier path, but it’s not the one most beneficiaries face when inheriting from a parent in their late 70s or 80s.

This case study assumes the harder path: decedent was already taking RMDs at death.

The case study: $500K inherited IRA, 45-year-old heir, $120K income

A 45-year-old marketing director in Denver inherits her father’s $500,000 traditional IRA in November 2025. Her father was 78 and had been taking RMDs since age 73. She is a non-spouse, non-eligible designated beneficiary — subject to the 10-year rule with annual RMDs.

Her numbers:

• Inherited IRA balance: $500,000 (as of December 31, 2025)
• Her age in 2026 (year after death): 46
• IRS Single Life Expectancy factor at age 46: 39.8 (Table I, IRS Publication 590-B)
• Assumed annual growth: 6% (applied to remaining balance after each year’s distribution)
• Her W-2 income: $120,000/year (single filer)
• Deadline to drain the account: December 31, 2035

Scenario 1: minimum annual RMDs (the default most people follow)

Each year, she divides the prior December 31 balance by her life expectancy factor. The factor starts at 39.8 and decreases by 1 each year. Whatever remains in the account after year 9’s RMD must come out in year 10.

Total distributed over 10 years: ~$798,081. That’s $298,081 more than the original $500K inheritance — the account grew while minimum RMDs barely scratched the surface.

The problem is obvious: $653,719 hits her tax return in a single year.

The year-10 tax bomb: bracket math at $120K base income

Her W-2 income is $120,000. After the standard deduction ($15,750 for single filers in 2026), her base taxable income is $104,250 — just into the 24% federal bracket (which starts at $103,351 for single filers).

In years 1–9, the small RMDs ($12,563–$20,023) stack on top of that base. The entire distribution lands in the 24% bracket. Tax on each year’s RMD: roughly $3,000–$4,800. Total federal tax on years 1–9 distributions: approximately $34,600.

Then year 10 hits. Adding $653,719 to $104,250 of base taxable income:

Effective tax rate on the year-10 distribution alone: 33.6%. Compare that to the 24% rate on years 1–9 distributions.

Total federal tax across all 10 years (minimum-RMD approach): ~$254,200.

Scenario 2: level distributions — same amount each year

Instead of minimum RMDs, she takes roughly equal annual distributions designed to drain the account by year 10. With 6% growth on a $500K starting balance, level annual withdrawals of approximately $79,500 achieve this.

Each $79,500 distribution adds to her $104,250 base taxable income, pushing her to ~$183,750. That stays entirely within the 24% bracket (which runs to $197,300 for single filers).

Total federal tax on distributions (level approach): ~$190,800.

The $63,400 gap: why spreading beats minimum RMDs

Side by side:

That $63,400 is not a rounding error. It’s the cost of letting the account grow tax-deferred into a single-year bracket explosion. The year-10 lump sum pushes income through the 32%, 35%, and 37% brackets — rates this beneficiary would never touch on her W-2 income alone.

The level approach keeps every dollar of distribution income in the 24% bracket. Same money out, dramatically less tax.

The part most articles skip: you can take MORE than the minimum RMD

The IRS sets a floor, not a ceiling. Your annual RMD is the minimum you must withdraw — you can always take more. This is what makes the level-distribution strategy possible: you take the minimum RMD plus an additional voluntary distribution each year to smooth the tax burden.

In year 1, the minimum RMD is $12,563. To hit the $79,500 level target, you withdraw an additional $66,937 voluntarily. The IRS doesn’t care that you took more than required — it only penalizes you for taking less.

When front-loading beats level distributions

The level approach assumes stable income for 10 years. Life doesn’t always cooperate. Front-loading — pulling larger distributions in the early years — wins when:

• You expect a job loss, sabbatical, or career change. If your income drops to $40,000 in a gap year, that’s room for $63,000 of inherited IRA distributions in the 12% bracket (single filer: 12% bracket runs from $11,926 to $48,475). Filling the 12% bracket in a gap year saves 12 percentage points vs. the 24% bracket in a normal year — roughly $7,500 per $63,000 of distributions pulled forward.
• You’re planning early retirement within the 10-year window. Retire at 52 (year 7 of the inherited IRA clock), and years 7–10 become natural low-income years for larger distributions at lower brackets.
• You expect tax rates to increase. The TCJA brackets were extended by OBBBA, but future legislation could raise rates. Taking more now at known rates hedges against that risk.

When back-loading wins (it’s rarer than you think)

Deferring distributions to later years works only when you have a specific, identifiable low-income event in the future:

• Planned move to a no-income-tax state. If you’re in California (13.3% top rate) now and planning to relocate to Texas or Florida in year 7, deferring large distributions until after the move saves the state tax. That’s a real savings of up to 13.3% on hundreds of thousands of dollars.
• Large deduction event. A major charitable donation year, a business loss carryover, or a year with substantial deductible expenses can absorb inherited IRA income.

Absent a concrete plan, back-loading just creates the year-10 bomb. “I’ll figure it out later” is not a tax strategy.

The 25% penalty for missed RMDs: don’t skip a year

Under IRC § 4974 as amended by SECURE 2.0 § 302, the excise tax on a missed RMD is 25% of the shortfall. If your year-3 RMD is $14,115 and you take $0, the penalty is $3,529 — on top of the income tax you’ll owe when you eventually take the distribution.

The penalty drops to 10% if you correct the shortfall within the IRS correction window (generally by the end of the second tax year following the year the penalty is assessed). File Form 5329, take the missed distribution, and request the reduced penalty.

The enforcement gap: the IRS waived penalties on missed inherited IRA annual RMDs for tax years 2021–2024 while the final regulations were in limbo. That waiver is over. Starting with the 2025 tax year (your 2026 filing), the 25% penalty is live. Beneficiaries who got comfortable skipping annual distributions during the waiver period now face real consequences.

Eligible designated beneficiaries: who escapes the 10-year rule

Not everyone is trapped in the 10-year window. Under IRC § 401(a)(9)(E), five categories of “eligible designated beneficiaries” can still stretch distributions over their own life expectancy:

1. Surviving spouse — can roll the inherited IRA into their own IRA, treat it as their own, and delay RMDs until their own RBD
2. Minor children of the decedent (not grandchildren) — stretch until the age of majority, then the 10-year clock starts
3. Disabled individuals (IRC § 72(m)(7))
4. Chronically ill individuals
5. Beneficiaries not more than 10 years younger than the decedent

Our 45-year-old Denver beneficiary doesn’t qualify for any of these. She’s 33 years younger than her father was at death, not a spouse, not disabled, not chronically ill. She’s in the 10-year rule, full stop.

Pre-2020 vs. post-2019 death: the date that decides your rules

The 10-year rule applies to accounts inherited from decedents who died on or after January 1, 2020 (the SECURE Act effective date). If the original owner died before 2020, the old “stretch IRA” rules still apply — the beneficiary can spread distributions over their own life expectancy with no 10-year deadline.

This article’s case study assumes a 2025 death. If you inherited an IRA from someone who died in, say, 2018, you’re under the old rules and the 10-year math here doesn’t apply to you.

Inherited Roth IRAs: same 10-year clock, completely different tax math

The 10-year depletion deadline applies to inherited Roth IRAs too. The difference: qualified Roth distributions are tax-free (assuming the original Roth was held at least 5 years before the owner’s death under IRC § 408A(d)(3)). So the 10-year rule is a timing constraint, not a tax event.

For inherited Roths, the math inverts: you generally want to leave the money in as long as possible to maximize tax-free growth, then drain it all in year 10. There’s no bracket penalty because there’s no taxable income. Annual RMDs are generally not required for inherited Roths regardless of the decedent’s RBD status, because Roth IRAs don’t have a required beginning date.

Decision tree: which withdrawal strategy fits your situation

Run through these questions in order:

1. Did the decedent die before or after their required beginning date?
   • Before RBD: no annual minimums required — you have full flexibility to time distributions within the 10-year window. Skip to question 3.
   • After RBD (like our case study): annual RMDs required in years 1–9. Take at least the minimum every year to avoid the 25% penalty. Continue to question 2.
2. What is your marginal federal tax bracket on W-2/base income alone?
   • Already at 32% or higher: you have less room to absorb distributions before hitting 35%/37%. Level distributions matter even more — run the bracket-fill math carefully.
   • At 22%–24% (like our case study): substantial room to absorb $60K–$80K of annual distributions within your current bracket. Level approach is likely optimal.
   • At 12% or lower: pull as much as you can into the 12% bracket every year. This is the cheapest income tax rate you’ll pay on inherited IRA money.
3. Do you expect a low-income year in the next 10 years?
   • Yes (job change, sabbatical, early retirement, parental leave): front-load distributions into that year. Fill the 12% and 22% brackets while they’re available.
   • No: default to level distributions across all 10 years.
4. Are you planning a move to a lower-tax or no-tax state?
   • Yes: defer larger distributions until after the move. The 9 states with no income tax (AK, FL, NV, NH, SD, TN, TX, WA, WY) save you the full state tax rate on every dollar of inherited IRA distribution.
   • No: state taxes don’t change the federal bracket-smoothing calculus, but add them to your total cost when modeling.
5. Is the inherited account a Roth IRA?
   • Yes: distributions are tax-free. Delay as long as possible — let the account grow tax-free and drain in year 10.
   • No (Traditional IRA): distributions are ordinary income. Smooth them across years to avoid bracket spikes.

Common mistakes that cost inherited IRA beneficiaries tens of thousands

1. Taking only the minimum RMD and ignoring the year-10 cliff. This is the most expensive default behavior. The IRS requires a minimum, but the minimum is a tax trap when the account keeps growing. Our case study shows a $63,400 cost for this mistake.
2. Missing the annual RMD entirely. The 2021–2024 waiver created a false sense of security. Starting 2025, the 25% excise tax is enforceable. Set a calendar reminder for December 1 each year.
3. Rolling an inherited IRA into your own IRA. Non-spouse beneficiaries cannot do this. If you roll inherited IRA funds into your own IRA, the entire amount is treated as a taxable distribution in the year of the rollover, plus a 10% early withdrawal penalty if you’re under 59½. This is an unforced $100K+ error.
4. Failing to retitle the account properly. An inherited IRA must be titled as “[Deceased Owner Name], deceased [date], IRA FBO [Beneficiary Name], beneficiary.” Improper titling can trigger a full taxable distribution.
5. Not modeling the IRMAA impact. For beneficiaries near Medicare age, large inherited IRA distributions inflate MAGI, which can trigger IRMAA surcharges on Medicare Parts B and D. At the highest tier, that’s $628.90/month in Part B premiums alone vs. $185/month at the base level — an additional $5,327/year per spouse.

The bottom line

A $500K inherited traditional IRA with 6% growth distributes roughly $798,000 over 10 years. The question isn’t whether you’ll pay tax — it’s whether you’ll pay it at 24% spread evenly or at 33.6% concentrated in year 10. That spread is worth approximately $63,400 in federal tax savings for a $120K earner. Run the bracket-fill math in year 1, not year 9. The year-10 lump sum is the most expensive way to inherit an IRA — and it’s the default path for anyone who just takes the minimum.