When Should I Consider a Roth Conversion After I Retire?
The years after work ends and before required distributions begin can create unusually low taxable income. Filling part of that space with planned Roth conversions may reduce later forced withdrawals—but the tax bill arrives now.
Why a Window Opens
Wages often stop at retirement, while required minimum distributions have not yet begun. Under current federal rules, RMDs generally start at 73 for people born in 1951-1959, and at 75 for those born in 1960 or later. Roth IRA owners do not take lifetime RMDs from their own Roth IRA. Those facts can create a planning window, particularly for someone retiring in their 60s.
A Roth conversion moves money from a traditional retirement account to a Roth account. The Internal Revenue Service says the untaxed portion converted is included in gross income for that year. There is no income limit on eligibility to convert, but the conversion can raise taxes, Medicare premiums, and other income-linked costs.
A conversion does not erase tax. It chooses a year to recognize taxable income in exchange for moving assets out of the future RMD calculation.
An Eight-Year Illustration
For an age-73 RMD cohort (birth years 1951-1959), consider an illustrative retiree with $1 million in a traditional IRA at age 65 who reaches 73 eight years later. This example is not the RMD timeline for someone born in 1960 or later. Assume the account grows 5% annually. With no withdrawals or conversions, the balance grows to about $1.48 million. Using the IRS Uniform Lifetime Table divisor of 26.5 at age 73, an illustrative first RMD is about $55,753.
Now assume the retiree converts $50,000 at the start of each year from age 65 through 72, then the remaining traditional balance grows 5%. After eight conversions, the traditional balance is about $976,127 and the illustrative first RMD is about $36,835.
Rounded nominal dollars. The $400,000 converted is not spending or a loss; it moves to a Roth account. Conversion taxes, Roth growth, market variation, fees, and other withdrawals are excluded.
The first RMD is roughly $18,918 lower in the conversion path. That does not prove the conversions saved money. A fair comparison must include the tax paid on each conversion, how that tax was funded, future tax rates, investment growth in both accounts, and the value of leaving Roth assets to heirs.
The Constraints That Matter
Tax brackets are marginal. A conversion can be sized to use a chosen bracket, but other income and deductions determine the actual room available.
Medicare looks back two years. A conversion at 63 or later can increase income-related Medicare premiums at 65 or later.
An RMD cannot be converted. The IRS requires the year’s RMD to come out first; only additional eligible funds can move to Roth.
Conversion tax needs a funding plan. Paying it from cash outside the IRA preserves more money inside retirement accounts, but that cash has an opportunity cost.
Conversions cannot be undone by recharacterization under current federal law. Scenario testing matters before execution.
A Better Question Than ‘Should I Convert?’
The useful question is how much to convert in each year under several futures. Compare no conversion, a fixed annual amount, and a tax-bracket ceiling. Then test a surviving spouse filing alone, because a similar household income can face narrower tax brackets and lower Medicare income thresholds after one spouse dies.
Model the conversion, not just the tax bracket
Compare Roth conversion strategies alongside estimated taxes, withdrawals, and RMDs. Medicare income-threshold warnings are available; premium costs and survivor benefits are not calculated automatically.
Sources: IRS, required minimum distribution FAQs; IRS Publication 590-B; IRS, IRA FAQs; and IRS Topic 309. The example applies a $50,000 conversion at the start of each year and 5% growth afterward. It assumes the age-73 divisor remains 26.5 and omits taxes, fees, market variability, Roth-account growth, and other distributions. Tax rules can change. This is educational information, not tax or financial advice.