Managing the tax impact of an inherited IRA requires strategic timing:
Pre-tax distributions are taxed as ordinary income. Waiting until year ten to liquidate a large pre-tax IRA creates a concentrated taxable event that can push you into the top 37% marginal bracket. To minimize the cumulative tax, spread the distributions over the ten-year window, utilizing years where your other income is temporarily lower or bracket thresholds are favorable.
A spike in adjusted gross income (AGI) from large IRA distributions can trigger secondary tax penalties. These include the phase-out of itemized deduction benefits, increased capital gains tax brackets, and higher Medicare Part B and Part D premiums via the IRMAA surcharge.
Inherited Roth IRAs are subject to the same ten-year rule, but distributions are completely tax-free. Because there are no annual RMDs required for inherited Roth IRAs (regardless of when the decedent died), the optimal strategy is to leave the funds in the account until the final year. This maximizes the period of tax-free compounding.