Tax Calculator
RMD Tax Cost Estimator: What It Calculates and How to Read the Result
Quick answer
The tax cost of RMDs is not just the federal and state income tax on the distribution itself. It's the cumulative effect of RMDs stacking on top of Social Security (which can push more of your benefit into the taxable range), pushing you into higher brackets, and triggering IRMAA Medicare premium surcharges that compound year after year. The total multi-year tax cost is typically 1.5–2× the headline tax on the RMD alone.
RMD Tax Cost Estimator
See what the IRS will collect from your pre-tax accounts, across your lifetime and your heirs. Adjust the sliders to personalize the two-generation tax projection.
Your Assumptions
RMDs start at 73 for someone born in 1955: age 73 if you were born 1951 to 1959, 75 if you were born in 1960 or later.
Two-Generation Tax Projection
What Doing Nothing Actually Costs
$1,910,120
IRA Balance at RMD Start (Age 73)
$593,477
Your Cumulative Tax (Ages 73–95)
$777,740
Heirs' Tax (10-Year SECURE Act Liquidation)
$1,371,217
Grand Total Two-Generation Tax Burden
27% of every dollar this IRA pays out goes to taxes across two generations
Think of a traditional IRA as a shared account: one portion belongs to you and your heirs, the rest is reserved for the IRS at whatever rate applies when the money comes out. Roth conversions stay allowed after RMDs begin at 73, but each year's RMD must come out first and cannot be converted, so every conversion after that age stacks on top of forced RMD income in the same tax year. The years before 73 are the cleanest window to shift the outcome. Every year of inaction compounds the exposure.
Annual RMD Amount & Cumulative Tax: Ages 73 to 95
First RMD at 73: $72K. By age 95: $185K annually, forced income, every year, whether needed or not.
Inherited IRA: 10-Year SECURE Act Forced Liquidation @ 37% Bracket
Because you had already started RMDs, your heirs must take an RMD every year and empty the account by the end of year 10. Every dollar comes out as ordinary income at their bracket, not capital gains.
Total Tax Paid Across Two Generations: Running Total
Same $1,700,000 IRA. Of the $5,069,383 it pays out across two generations, 27 cents of every dollar goes to taxes.
- Tax drag / lifetime taxes: ~1,371,217
- Potential RMD spike
- Potential RMD spike at age 73
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Educational estimates only. RMDs use the IRS Uniform Lifetime Table from the final regulations effective in 2022 (Treas. Reg. 1.401(a)(9)-9). SECURE 2.0 sets the start age: 73 if born 1951 to 1959, 75 if born 1960 or later. The first RMD is assumed to be taken in the year you reach that age; delaying it to April 1 of the next year puts two RMDs in one tax year. For a married couple, the surviving spouse is assumed to roll the IRA over and keep taking RMDs, and "Project Through Age" is the age at the second death. A spouse more than 10 years younger could use the smaller Joint Life Table RMD instead. Your rate is a single blended effective rate: include federal tax plus Arizona's 2.5% flat tax in 2026, and raise it for the years a survivor files single. It does not model bracket changes, the senior deduction, Social Security taxation, NIIT, or IRMAA. In 2026, qualified charitable distributions of up to $111,000 per owner can satisfy RMDs tax-free and would lower these figures. Heirs are assumed to be non-spouse beneficiaries under the 10-year rule: the inherited balance keeps growing at your rate and is paid out in level annual amounts that empty it in 10 years, which also meets the annual-RMD requirement for heirs younger than about 81. Figures are nominal and not discounted. Actual outcomes depend on tax law changes, investment returns, withdrawal timing, and individual circumstances. Consult a qualified tax and financial planning professional before making decisions.
What This Calculator Actually Answers
This calculator projects your full tax cost from RMDs across a 20-year horizon, not just the direct income tax on the distribution, but the second-order effects: how RMDs change the taxable portion of your Social Security, which IRMAA tier you fall into (with its 2-year lookback), and what your marginal federal and state bracket becomes once RMDs are stacked on top of all other income.
For a household with $2M+ in pre-tax accounts entering RMDs, the cumulative tax cost over 20 years routinely exceeds $500,000. The number is large because RMDs grow as a percentage of the balance (the IRS divisor shrinks each year), and because the IRMAA and Social-Security-taxation effects compound.
How to Read the Result
The single most important read is the comparison between your projected tax cost with current planning versus the projected cost if you executed a multi-year Roth conversion strategy in the pre-RMD years. For most households with $1.5M+ in pre-tax accounts and a 5–10 year pre-RMD window, deliberate conversion reduces the lifetime RMD tax cost by 25–50%.
Also pay attention to the IRMAA tier trajectory. If your projected income places you in an IRMAA tier for 10+ consecutive years, that's $5,000–$50,000+ in additional Medicare premium cost on top of the income tax. A cost most retirees do not anticipate when they project RMDs in isolation.
Common Mistakes
- Calculating only the direct income tax on the RMD without modeling Social Security taxation and IRMAA. These second-order effects are often 50%+ of the total cost.
- Assuming static tax law over a 20-year horizon. The 2017 TCJA provisions were scheduled to sunset after 2025, but the 2025 One Big Beautiful Bill Act made the individual rates and elevated standard deduction permanent, projections built before that law passed are now overstating future tax rates.
- Forgetting that RMDs are calculated separately for each 401(k) but aggregated for IRAs. Rolling old 401(k)s to an IRA can simplify the calculation but may forfeit other benefits.
- Failing to consider Qualified Charitable Distributions if you have charitable intent. QCDs satisfy the RMD without counting as taxable income, one of the most powerful tax tools available to RMD-age households.
- Not coordinating with capital-gain realization. Large RMDs combined with deliberate gain harvesting in the same year can push gains out of the 0% LTCG bracket entirely.
When This Calculator Is Not the Right Tool
This tool projects the cost of doing nothing. The actual planning lever, the Roth conversion strategy that reduces the projected cost, is modeled by the Roth Conversion Bracket Analyzer. Use this calculator to quantify the problem; use the Roth analyzer to design the solution.
Frequently Asked Questions
How much can deliberate Roth conversions reduce the lifetime RMD tax cost?
For households with $1.5M+ in pre-tax accounts and a 5–10 year pre-RMD window, deliberate Roth conversion strategy typically reduces the lifetime RMD tax cost by 25–50%. The exact figure depends on your starting balance, your bracket trajectory, your charitable intent, and how aggressively you can convert within IRMAA and bracket constraints.
Does Social Security really get taxed more because of my RMDs?
Yes. The taxable portion of Social Security depends on your 'provisional income,' which includes RMDs. As provisional income rises, more of your Social Security gets pulled into the taxable range, up to a maximum of 85% of the benefit. For most retirees with significant pre-tax accounts, RMDs push Social Security taxation to the 85% maximum, meaning every dollar of additional income is also taxing your Social Security further.
What is the widow's penalty?
When the first spouse dies, the surviving spouse moves from married-filing-jointly tax brackets to single-filer brackets, typically a much narrower set of brackets that pushes the same income into materially higher rates. RMDs continue largely unchanged, but the tax bill jumps. Forward-looking planning often involves accelerating Roth conversions before the first death to reduce the widow's penalty.
Can I use Qualified Charitable Distributions to satisfy my RMD?
Yes. QCDs (up to $111,000/year in 2026, indexed annually) count toward your RMD and are excluded from your taxable income. For charitably inclined RMD-age retirees, QCDs are often the most efficient charitable strategy, better than taking the RMD into income and then deducting a contribution.