Traditional vs Roth 401(k): Which Should You Choose?

Written by Muhammad Ajmal · Published May 1, 2026 · Updated Sep 24, 2026

The core difference is when you pay tax. Traditional 401(k) contributions come out of your pay before income tax, so you save tax now and pay it when you withdraw in retirement. Roth 401(k) contributions are taxed now, but qualified withdrawals, including all the growth, are tax-free later. If your tax rate in retirement will be higher than today, Roth tends to win. If it'll be lower, traditional tends to win.

Why they're equal if your tax rate doesn't change

Say you're in the 22% bracket and set aside $5,000 of pay.

• Traditional: the full $5,000 goes in, costing you $3,900 of take-home pay (you skip $1,100 of tax). At 7% for 30 years it grows to about $38,060. Withdraw it at 22% tax and you keep about $29,690.
• Roth: you pay the tax first, so $3,900 goes in. At 7% for 30 years that grows to about $29,690, tax-free.

Same result. The choice only matters because tax rates are different at different points in your life, and nobody knows exactly what they'll be.

When Roth usually makes sense

• You're early in your career and in a low bracket (10% or 12%). Your income, and tax rate, will probably rise.
• You expect a big pension or other income in retirement, which would push your withdrawals into a higher bracket.
• You want tax diversification. Having both pre-tax and tax-free money gives you flexibility to manage your tax bill each year in retirement.
• You think tax rates overall will be higher in future. That's a guess, but a common one.

When traditional usually makes sense

• You're in your peak earning years in the 24% bracket or above, and expect a lower income in retirement.
• You need the tax break now to afford to save at all. Saving more in traditional beats saving less in Roth.
• You plan to retire somewhere with lower or no state income tax than where you work now.

Things that work the same either way

• Contribution limit: it's shared. For 2026 that's $24,500 total across traditional and Roth, plus catch-up if you're 50+. See 401(k) limits for 2026.
• Employer match: historically always pre-tax. Since SECURE 2.0, employers are allowed to offer Roth matching, but many still put the match in the traditional side.
• Early withdrawals: both generally have penalties before 59½, with some exceptions.

A few Roth-specific details

• No required minimum distributions from Roth 401(k)s while you're alive, starting in 2024. Traditional 401(k)s have RMDs, currently from age 73.
• The five-year rule: for tax-free withdrawal of earnings, the account generally needs to be at least five years old and you need to be 59½ or older.
• High earners and catch-ups: from 2026, if you earned more than $150,000 in FICA wages from your employer the previous year, your catch-up contributions have to go in as Roth.

Can't decide? Split it

There's nothing wrong with putting half in each. It hedges your bets on future tax rates and gives you both kinds of money to draw on later. Some people start mostly Roth in their 20s and shift towards traditional as their income climbs.

How much to contribute at all

The Roth vs traditional question matters less than the amount you save. Get your full employer match first, then work up from there. How much should I contribute to my 401(k)? covers that, and the 401(k) calculator projects your balance. For how a Roth IRA fits in, see Roth IRA vs traditional IRA and 401(k) vs IRA.

Tax rules are detailed and your situation is unique, so for big decisions it's worth talking to a tax professional or fee-only financial planner.

Frequently asked questions

Keep reading

• 401(k) vs IRA: Where Should Your Next Dollar Go?
• What Happens to Your 401(k) When You Leave a Job?
• 401(k) Contribution Limits for 2026 (and Catch-Up Rules)
• How Much Should I Contribute to My 401(k)?