How This Calculator Works

This calculator models year-by-year Required Minimum Distributions for inherited IRAs under the SECURE Act and the 2024 final regulations. It determines which rule applies from the beneficiary type and the owner's dates of birth and death. Where a deadline leaves room to choose (the 10-year rule, and a minor child's deadline), it compares three distribution strategies by their federal income tax in today's dollars.

Rule Determination Logic

The calculator first determines which distribution rule applies:

// Year 1 is the calendar year after the owner's death.
if (relationship === 'spouse')                  // sole beneficiary
  → roll over / treat as own, or keep as inherited:
    yearly minimum over the spouse's life expectancy, looked up again each year;
    owner died before the RBD: may wait until the year the owner would have reached RMD age

if (relationship === 'non-spouse-eligible' || 'disabled-chronically-ill')
  → yearly minimum over the beneficiary's life expectancy, reduced by one each year,
    until the factor reaches 1 (no fixed deadline while the beneficiary lives)

if (relationship === 'minor-child')
  → the same yearly minimums until 21; everything out by 31 December of the year
    of the 31st birthday (the 10th anniversary of the 21st)
  → a child already 21 at the owner's death is not a minor: 10-year rule

if (relationship === 'non-spouse-non-eligible')
  → 10-year rule: everything out by 31 December of the 10th year after death
  → owner died on or after their RBD (traditional IRA):
      yearly minimums in years 1-9, from 2025 (2021-2024 waived, Notice 2024-35)
  → owner died before their RBD, or a Roth IRA:
      no yearly minimums

Required Beginning Date (RBD)

The Required Beginning Date is April 1 of the year after the year the IRA owner reaches their RMD age, and that age depends on when they were born: 70½ if they reached 70½ before 2020 (born before July 1949), 72 if born July 1949 to December 1950, 73 if born 1951 to 1959, and 75 if born 1960 or later. The calculator asks for the owner's birth month and year and the month and year they died, and works out the date. An owner who died during the year they reached their RMD age, or before April 1 of the next year, died before their RBD (IRS Publication 590-B).

Authority: SECURE 2.0 Act of 2022, Section 107, amending IRC Section 401(a)(9)(C)(i).

Single Life Expectancy Table

Every yearly minimum is the balance at the end of the previous year divided by a life expectancy factor from the Single Life Table (26 CFR 1.401(a)(9)-9(b), Table I in Publication 590-B, updated for 2022 and later).

Every non-spouse beneficiary, eligible or not, uses their age in the year after the owner's death, then reduces that factor by 1 each year. It is not looked up again (26 CFR 1.401(a)(9)-5(d)(3)(iii)). The calculator works out that age from the age you enter and the year of death.
A surviving spouse who is the sole beneficiary looks the factor up again each year at their age that year ((d)(3)(iv)). If the owner died before their RBD, the spouse may wait until the end of the year the owner would have reached RMD age (1.401(a)(9)-3(d)).
If the owner died on or after their RBD, the factor is the greater of the beneficiary's and the owner's remaining life expectancy. The owner's starts at their age in the year of death and drops by 1 each year ((d)(1)(ii), (d)(3)(ii)). This matters when the beneficiary is older than the owner.
When the factor reaches 1 or less, everything left comes out that year.

// Annual RMD calculation (when required)
RMD = Account Balance / Life Expectancy Factor

// Non-spouse: factor reduces by 1 each year
Year 1 factor = Table I lookup(beneficiary age)
Year 2 factor = Year 1 factor - 1
Year N factor = Year 1 factor - (N - 1)

// Example: beneficiary age 45
Year 1: $500,000 / 41.0 = $12,195
Year 2: $517,073 / 40.0 = $12,927  (balance after year 1 withdrawal, grown 6%)
...
Year 10: remaining balance (must withdraw everything)

// Example: eligible beneficiary age 60, 0% return
Every year: $500,000 / 27.1 = $18,450 (the divisor falls by 1 as the balance does)
Year 28: divisor 0.1, so the last $1,845 comes out

Authority: IRS Publication 590-B, Appendix B, Table I — Single Life Expectancy (updated 2022).

Tax Calculation

Federal income tax on distributions is calculated using 2026 tax brackets (IRS Rev. Proc. 2025-32) with the standard deduction. The calculator computes the incremental tax on each distribution — the additional tax caused by adding the distribution to the beneficiary's existing income.

// 2026 Federal Tax Brackets (Single)
10%: $0 – $12,400
12%: $12,400 – $50,400
22%: $50,400 – $105,700
24%: $105,700 – $201,775
32%: $201,775 – $256,225
35%: $256,225 – $640,600
37%: Over $640,600

// 2026 Standard Deduction
Single: $16,100
Married Filing Jointly: $32,200

// Incremental tax on distribution:
tax = totalTax(baseIncome + distribution) - totalTax(baseIncome)
// where baseIncome is the beneficiary's other annual income

Limitation: This calculator models federal income tax only. State income taxes, IRMAA surcharges, and net investment income tax (NIIT) are not included. Consult a tax professional for a complete analysis.

Distribution Strategies

Where a deadline applies (the 10-year rule, or a minor child's deadline), the calculator compares three strategies. Each one always takes at least the year's required minimum, and everything left in the deadline year. On the open-ended life-expectancy paths (spouse, disabled, chronically ill, not more than 10 years younger) only the yearly minimums are shown, and there is no comparison.

Strategy A: Minimum RMDs + Lump Sum Year 10

If annual RMDs are required (decedent died after RBD), take only the minimum each year using the life expectancy table. If no annual RMDs are required (decedent died before RBD), take $0 in years 1-9. In both cases, the remaining balance is withdrawn in year 10.

Pros: Maximizes tax-deferred growth. Cons: Creates a large taxable event in year 10 that may push into higher brackets.

Strategy B: Even Distribution

Uses the PMT (payment) formula to calculate a fixed annual withdrawal that drains the account to exactly $0 by year 10, accounting for investment growth:

// PMT formula (annuity due: withdraw at the start of the year, the rest grows)
if (returnRate === 0):
  PMT = balance / years
else:
  PMT = (balance × r × (1+r)^(n-1)) / ((1+r)^n - 1)
  where r = expectedReturnRate, n = totalYears
distribution = max(PMT, requiredMinimum)

Pros: Smooths tax liability across all years. Cons: May not be optimal if income varies significantly year to year.

Strategy C: Front-Loaded (Bracket Optimization)

Takes larger distributions in early years, targeting the beneficiary's current marginal tax bracket ceiling. Each year, the distribution is the larger of: (a) 1.5x the bracket room (space remaining in the current bracket), or (b) the minimum required to drain the account by the deadline.

Pros: Reduces future bracket risk if income is expected to rise. Cons: Sacrifices some tax-deferred growth.

Which strategy costs least

Strategies are ranked by federal tax in today's dollars: each year's tax is discounted back to year 1 at your expected return. Simply adding up the years' taxes would mislead. Money left in the account grows, so a strategy that withdraws later pays more tax in nominal dollars even when it costs less. If the money you take out earns the same return outside the account, the strategy with the lowest tax in today's dollars is also the one that leaves you the most after tax. Tax on the reinvested money outside the account is not modelled; that drag favours keeping money in the inherited IRA longer.

taxInTodaysDollars = Σ tax(year i) / (1 + r)^(i − 1)
lowestTax = strategy with the smallest taxInTodaysDollars
saving    = costliest − lowest (in today's dollars)

Excise Tax Penalty

SECURE 2.0 (Section 302) reduced the excise tax penalty for missed RMDs from 50% to 25% of the shortfall amount. If the shortfall is corrected within 2 years (by taking the missed distribution and filing Form 5329), the penalty is further reduced to 10%.

// Excise tax penalty
Standard penalty = missed_amount × 25%
Corrected within 2 years = missed_amount × 10%

// Example: $50,000 missed RMD
Standard: $50,000 × 25% = $12,500
Corrected: $50,000 × 10% = $5,000

Authority: SECURE 2.0 Act of 2022, Section 302, amending IRC Section 4974.

Key Regulatory Sources

Final RMD regulations, T.D. 10001 (July 2024) — 26 CFR 1.401(a)(9)-5(d)(1): annual RMDs are required every year when the decedent died on or after the RBD, on top of the 10-year deadline, with the greater of the beneficiary's and the owner's remaining life expectancy; (d)(3): how each life expectancy is set and reduced; (e)(2) and (e)(4): the 10-year deadline and a minor child's deadline; 1.401(a)(9)-3(d): the surviving spouse's permitted delay; 1.401(a)(9)-4(e)(3): majority at 21. They apply from 2025.
IRS Notices 2022-53, 2023-54 and 2024-35 — no excise tax on missed annual RMDs for 2021 to 2024 while the regulations were pending. Notice 2024-35 is penalty relief and an applicability date, not the regulations themselves (this page said otherwise until October 2026).
SECURE Act of 2019 (Pub. L. 116-94) — Established the 10-year rule for non-eligible designated beneficiaries, effective for deaths after December 31, 2019.
SECURE 2.0 Act of 2022 (Pub. L. 117-328) — Raised the RMD age to 73 (and to 75 for owners born in 1960 or later, IRC §401(a)(9)(C)(v)), reduced excise penalty from 50% to 25% (Section 302), and added 10% corrective provision.
IRS Publication 590-B — Distributions from Individual Retirement Arrangements. Contains Single Life Expectancy Table (Table I) and detailed rules for inherited IRAs.
IRC Section 401(a)(9) — The statutory basis for all required minimum distribution rules, including inherited IRA provisions.

Limitations and Assumptions

Uses 2026 federal tax brackets — actual brackets may differ in future years due to inflation indexing.
Does not model state income taxes, IRMAA, or NIIT.
Assumes constant annual income and expected return rate across all projection years.
Standard deduction is applied (does not model itemized deductions).
Roth inherited IRA distributions are assumed to satisfy the 5-year rule and are fully tax-free.
Minor child age of majority is set at 21 (per IRS rules, not state-specific ages).
Assumes a single beneficiary (for a spouse, the sole beneficiary) and an IRA that offers life-expectancy payments; an eligible beneficiary who chooses the 10-year rule instead, and the 10-year limit after an eligible beneficiary's own death, are not modelled.
The schedule runs from the year after death on the balance at death; years before this one are shown as if taken on schedule.
Ages are whole years: the age you enter is taken as your age this year and moved to the year after the owner's death (one year older if the death was this year).

Inherited IRA RMD Calculator — Methodology