Updated July 28, 2026. Quick answer: A large charitable deduction needs taxable income to be worth anything. A conversion creates exactly that. Bunching several years of intended giving into a conversion year can make the conversion substantially cheaper and the giving more tax-efficient at once.
Two things that need each other
A deduction with no income behind it is wasted. Conversion income with no deduction against it is taxed in full. Deliberately putting them in the same year improves both.
This is the same logic as bunching giving to clear the standard deduction, applied to a year you have chosen to create income in.
Give appreciated shares, not cash
Donating long-held appreciated stock generally deducts the full value while the embedded gain is never taxed — see the comparison. Paired with a conversion that is two tax benefits from one action.
Deduction ceilings are expressed as percentages of adjusted gross income, and a conversion raises AGI — which can actually increase how much of a gift is deductible this year. The interaction generally runs in your favour, but the ceilings differ by gift type and this is worth modelling rather than assuming.
A donor-advised fund separates the two decisions
Contribute in the conversion year, take the deduction then, and grant to charities over following years — see how that works. It is the usual vehicle when the giving intent is real but the recipients are not yet decided.
Sources
IRC §408A (Roth IRAs); IRC §408A(d)(3); IRC §402(c)(11) (inherited plan amounts); IRC §170 (charitable deduction); IRC §172 (net operating losses); SECURE Act (2019) and final RMD regulations published 19 July 2024. Cross-checked July 2026 against professional analyses. Indexed thresholds, aid formulas and state Medicaid rules are described rather than asserted — they change annually and by state.
This states what the cited authority says. It is not tax advice.