Inherited IRA + Roth Conversion Coordinator

Model how coordinating inherited IRA withdrawals with Roth conversions from your own traditional IRA changes total taxes across the SECURE Act 10-year window.

What this models

Strategy A: Equal inherited IRA withdrawals (1/10 of original balance per year), no Roth conversions from own IRA. Own traditional IRA compounds untouched for 10 years.

Strategy B: Same inherited IRA withdrawals, plus Roth conversions from your own IRA each year. Conversions fill your target bracket ceiling — stopping when the ceiling is hit or your own IRA is depleted. The conversion amount changes year-to-year as the own IRA balance shifts.

What this doesn't model

• State income taxes — can add 4–13% on top of federal in high-tax states
• IRMAA surcharges — large conversions can trigger Medicare Part B/D premium spikes if MAGI exceeds IRMAA thresholds
• Net Investment Income Tax (NIIT) — 3.8% on investment income above $200K single / $250K MFJ
• Future bracket inflation adjustments — the 2026 brackets shown here are used throughout; real thresholds adjust annually
• Annual RMD requirements — if the original IRA owner died after their Required Beginning Date, you may owe annual RMDs (not just a lump at year 10). See the 10-year rule guide for T.D. 10001 details
• Future RMD tax savings — Strategy B's smaller own IRA generates far less future RMD income. That downstream tax benefit is real but requires full retirement-income modeling to quantify

This tool gives directional insight, not a tax plan. The inputs that matter most for whether Strategy B wins: how much bracket space exists above your other income, the relative sizes of the inherited vs. own IRA, and your future ordinary income trajectory.

The case for coordinating — and when it doesn't apply

The core logic: inherited IRA withdrawals are unavoidable and taxed as ordinary income. If they push you into a bracket but don't fill it, the remaining space is an opportunity. Roth conversions from your own IRA in that space cost you taxes now at the same rate you'd pay on future RMDs — but the future Roth withdrawals are tax-free.

Strong case for coordination (Strategy B likely wins): You have low-income years during the 10-year window (pre-Social Security, early retirement, between jobs). Your own IRA is large relative to expected future income. Bracket space consistently opens up above inherited IRA withdrawals.

Weak case for coordination: Other income already fills your target bracket. You expect income to drop sharply in the future (conversions now may be at higher rates than future RMDs). You need current cash flow and conversions would require selling taxable investments to pay the tax bill.