Roth vs Traditional 401(k)
Pay taxes now or pay them later? The answer depends on your current bracket, your retirement bracket, and a few wrinkles most articles skip.
Traditional 401(k) wins if your tax rate will be lower in retirement; Roth wins if it will be higher. Young earners, future high earners, and anyone wanting tax-free flexibility lean Roth. High earners at peak income lean traditional. Splitting contributions hedges uncertainty.
The core tradeoff
Traditional contributions reduce your taxable income now; you pay ordinary income tax on withdrawals in retirement. Roth contributions are taxed now; qualified withdrawals in retirement are tax-free. If your marginal rate is identical now and in retirement, the math ties exactly.
The decision is therefore a tax-rate forecast. A 25-year-old in the 12 percent bracket will almost surely face higher rates later: Roth. A 55-year-old in the 35 percent bracket facing a lower retirement income: traditional.
The wrinkles that matter
Required minimum distributions apply to traditional balances starting at 73, forcing taxable withdrawals whether you need the money or not. Roth 401(k)s no longer have RMDs for the original owner under SECURE 2.0, a meaningful flexibility win.
Traditional contributions also lower your adjusted gross income today, which can reduce Medicare premiums, student loan payments on income-driven plans, and ACA subsidy cliffs. Roth contributions do none of that.
The hedge: split it
Nobody knows future tax rates, including Congress. Contributing to both gives you taxable and tax-free buckets in retirement, letting you manage your bracket year by year: pull from traditional up to a bracket limit, then switch to Roth.
A common split: traditional 401(k) up to the match and beyond during peak earning years, Roth IRA on the side every year. You get the deduction where it is most valuable and tax-free growth where it is cheapest.
Early-career special cases
In years with unusually low income, a gap year, graduate school, early retirement before Social Security, Roth contributions and Roth conversions are at their cheapest. These are the years to stuff the Roth bucket.
Conversely, in a peak bonus year, traditional contributions shield income at your highest marginal rate. Match the contribution type to the year's tax picture, not to a fixed rule.
Estate and legacy angles
Roth accounts are superior for heirs: beneficiaries get tax-free withdrawals, while inherited traditional accounts create taxable income. If leaving money matters, Roth has a clear edge.
Charitable givers should note the reverse: traditional IRA assets given directly to charity via qualified charitable distributions avoid tax entirely, making traditional balances the best charitable funding source.
Skip the arithmetic
Model either contribution type with the free retirement calculator.
Roth versus traditional
Should a young person choose Roth or traditional?
Usually Roth. Workers in their 20s are generally in the lowest tax bracket of their lives, so the deduction from traditional contributions is worth little while the tax-free growth of Roth is worth a lot. The exception is a young high earner already in a top bracket.
Can I have both Roth and traditional 401(k)?
Yes, most plans allow both. Your traditional plus Roth contributions share the single employee limit, $24,500 for 2026, so a split like $14,500 traditional and $10,000 Roth is fine. Employer matches go to the traditional side.
Do Roth 401(k)s have required minimum distributions?
No. Starting in 2024 under SECURE 2.0, Roth 401(k) accounts are exempt from required minimum distributions for the original owner, just like Roth IRAs. This removed one of the traditional 401(k)'s last structural advantages.