The standard advice on Roth versus Traditional IRA is wrong for at least half the people who hear it. The advice runs that Roth is best for young people in low brackets, and Traditional is best for high earners in peak brackets. That heuristic is true on average and false for individual cases. The decision is simpler than the calculators make it look once a person asks the right question.
The mechanics first. A Traditional IRA contribution reduces taxable income in the year of the contribution. The money grows tax-deferred. Withdrawals in retirement are taxed as ordinary income at the marginal rate at that time. Required Minimum Distributions begin at age 73 under current law. A Roth IRA contribution does not reduce taxable income in the year of the contribution. The money grows tax-free. Withdrawals after age 59 and a half, on accounts open at least five years, are entirely tax-free. There are no RMDs on Roth IRAs.
The 2026 contribution limit is $7,500 for both Traditional and Roth, with a $1,100 catch-up for taxpayers age 50 and over. Direct Roth contributions phase out at modified adjusted gross income of $169,000 for single filers and $251,000 for married filing jointly. Above those numbers, the backdoor Roth conversion is the path. Traditional IRA deductibility phases out at $89,000 single and $143,000 joint when the taxpayer is covered by a workplace retirement plan.
The standard framework compares the marginal tax rate today to the expected marginal tax rate in retirement. If today's rate is higher, the math favors Traditional. If retirement's rate is higher or equal, the math favors Roth. The mistake the calculators make is treating retirement tax rate as a static input. Two factors most people miss change the math.
The first is that Traditional IRA withdrawals affect Social Security taxation, Medicare premiums, and the tax bracket the same dollar lands in. A retired couple drawing $48,000 from Social Security and pulling $40,000 from a Traditional IRA for living expenses can find that 50 to 85 percent of their Social Security becomes taxable, their Medicare Part B premium increases by $200 to $440 a month under IRMAA, and their effective marginal rate climbs above what it was during their working years. Roth withdrawals do not count toward provisional income for Social Security taxation, do not trigger IRMAA brackets, and do not push anyone into a higher bracket. The retirement marginal rate on Roth is functionally zero.
The second factor is RMDs. A Traditional IRA holder at age 73 has to take a withdrawal whether they need the money or not. The withdrawal is taxable. A retiree with $1.4 million in a Traditional IRA at age 73, calculated against the IRS Uniform Lifetime Table divisor of 26.5, must withdraw $52,830 in year one. That is income they did not choose to take and cannot defer. Roth IRAs have no RMDs during the original owner's lifetime. The money compounds tax-free until death and passes to heirs with significant tax advantages.
The right question is not what marginal rate will I be in during retirement. The right question is what level of control over future taxable income do I want to keep. Roth gives total control. Traditional removes control at age 73 and ties retirement income to the future tax code, which a person cannot predict.
A working framework runs four scenarios. A young earner under age 35 in the 22 percent bracket or below should default to Roth. The compounding window is 30-plus years and the rate is low enough that the deduction is not worth losing the tax-free growth. A peak-earnings worker in their 40s and 50s in the 32 to 37 percent bracket should default to Traditional, but only for the years they expect rates to step down meaningfully in retirement. If they expect to retire in roughly the same bracket because of high portfolio income, they should still favor Roth.
A small business owner with variable income across years should split. Make Traditional contributions in the highest-income years and Roth contributions or conversions in the lower-income years to fill the lower brackets. This is the strategy Wesley uses. In a year with $186,000 of Lumina Media income, Traditional. In a year with $98,000 because of an equipment year or sabbatical, Roth or even partial conversion of the Traditional balance.
A taxpayer in their 60s who is already retired or semi-retired should run Roth conversions during the gap years between retirement and Social Security claiming. These are the lowest-income years of a working life. Converting $30,000 to $50,000 a year at the 12 percent bracket from a $900,000 Traditional IRA cuts future RMD impact and IRMAA risk substantially.
Tennessee has no state income tax, which removes one variable. In states with high income tax like California or New York, Traditional contributions get an additional state deduction that Roth does not, and that argues for Traditional during high-state-tax working years and Roth conversions after a move to a no-state-tax retirement state. Tennessee retirees do not have that lever.
The clean default for anyone making the decision once and walking away is Roth. The math is closer than the calculators show, the tax rules favor Roth on the back end, and control of future income is worth giving up the marginal deduction today.
Pick the account that lets you control your own retirement income. That is Roth in most cases.
