What Is a Roth 401(k)? How It Differs from a Traditional 401(k)

A Roth 401(k) is an employer-sponsored retirement account that combines the high contribution limits of a traditional 401(k) with the tax-free withdrawal rules of a Roth IRA. Contributions are made with after-tax dollars, and qualified withdrawals in retirement are completely tax-free.

How a Roth 401(k) Works

When you contribute to a Roth 401(k), you do not get a tax deduction today. Instead, your money grows tax-free, and you pay no taxes when you withdraw it in retirement — including on all the investment gains.

To take tax-free qualified distributions, you must:

  • Be at least age 59.5
  • Have held the account for at least five years

Roth 401(k) vs. Traditional 401(k): Key Differences

Feature Roth 401(k) Traditional 401(k)
Contributions After-tax Pre-tax
Tax deduction now No Yes
Withdrawals in retirement Tax-free Taxed as ordinary income
Required minimum distributions None (after 2024, per SECURE 2.0) Start at age 73
Income limits None None

2026 Contribution Limits

The 2026 contribution limit for a Roth 401(k) is the same as a traditional 401(k):

  • Under age 50: $23,500
  • Age 50–59 or 64+: $31,000 (includes $7,500 catch-up)
  • Age 60–63: $34,750 (higher catch-up under SECURE 2.0)

You can split contributions between Roth and traditional 401(k) in any proportion, as long as the combined total does not exceed the annual limit.

No Income Limits

Unlike a Roth IRA, a Roth 401(k) has no income limits. High earners who are phased out of direct Roth IRA contributions can still contribute to a Roth 401(k) if their employer offers one.

Employer Match in a Roth 401(k)

Your employer can match contributions to your Roth 401(k). Starting in 2026, employers can credit matching contributions directly to your Roth 401(k) (not just the traditional pre-tax side), though some employers still default to the pre-tax account. Check your plan documents to see how your employer handles matching.

No Required Minimum Distributions

Under the SECURE 2.0 Act, Roth 401(k) accounts no longer have required minimum distributions (RMDs) starting in 2024. Previously, Roth 401(k)s did require RMDs — a disadvantage over Roth IRAs. That disadvantage is now gone.

When a Roth 401(k) Makes Sense

You expect to be in a higher tax bracket in retirement. Paying taxes now at a lower rate, then withdrawing tax-free later, is the core appeal. Young workers early in their careers often fit this profile.

You have a long time horizon. Tax-free compounding over decades creates a powerful advantage. The longer the money grows, the more valuable the tax-free treatment becomes.

You want tax diversification. Having both a Roth 401(k) (tax-free bucket) and a traditional 401(k) (pre-tax bucket) gives you flexibility in retirement to manage your taxable income year by year.

When a Traditional 401(k) May Be Better

If you are currently in a high tax bracket and expect to be in a lower bracket in retirement, a traditional 401(k) may save you more in taxes overall. The tax deduction today is more valuable when your marginal rate is high.

Rolling Over a Roth 401(k)

When you leave a job, you can roll your Roth 401(k) balance directly into a Roth IRA without taxes or penalties. This eliminates any future RMD concern and consolidates your accounts.

Bottom Line

A Roth 401(k) is an excellent tool for workers who want the convenience of payroll-deducted contributions, high limits, and no income cap — combined with the tax-free retirement income of a Roth account. If your employer offers it, it is worth seriously considering, especially if you are young or expect your income to rise.