Roth 401(k) Gains: When You Pay Taxes and When You Don’t

Investment gains inside a Roth 401(k) come out completely free of federal income tax when the withdrawal is a qualified distribution, and they are taxed as ordinary income (usually with a 10% penalty on top) when it isn’t. Taxes on Roth 401(k) gains turn on two things: how long you’ve held the account and why you’re taking the money out. Get both right, and every dollar of growth is yours. Miss either one, and the earnings portion of whatever you withdraw lands on your tax return.

When Your Gains Come Out Tax-Free

A qualified distribution from a Roth 401(k) is entirely free of federal income tax on both your original contributions and every dollar of investment growth. Two conditions have to be satisfied at the same time:

At least five full tax years have passed since your first Roth contribution to that employer’s plan.
You’ve reached age 59½, become permanently and totally disabled, or the distribution is being made to a beneficiary after your death.¹

Both boxes have to be checked at once. If you’re 62 but you only opened the account three years ago, the earnings you pull out are taxable. If you’ve held the account for seven years but you’re only 50, the earnings are taxable. Only when age and time in the plan line up does the growth escape tax entirely.²

One boundary worth flagging: the $10,000 first-time homebuyer exception that makes a Roth IRA distribution qualified does not exist for Roth 401(k)s. Buying a first home before 59½ produces a non-qualified distribution from a Roth 401(k).³

How the Five-Year Clock Works

The clock starts on January 1 of the tax year in which you make your first Roth contribution to that employer’s plan. Contribute for the first time in November 2024 and you satisfy the five-year requirement on January 1, 2029.¹

What Changing Jobs Does to the Clock

Each employer’s Roth 401(k) has its own clock. Four years of contributions at your old job don’t automatically count toward a new employer’s plan; the new plan’s clock starts fresh.⁴

There is one way to preserve your holding period. If you do a direct plan-to-plan rollover from the old Roth 401(k) into the new employer’s Roth 401(k), the new plan can use the earlier of the two start dates as its clock. This only works for direct rollovers between employer plans, not rollovers to a Roth IRA.⁴

Rolling to a Roth IRA Uses a Different Clock

Roll your Roth 401(k) into a Roth IRA and the Roth IRA’s own five-year period controls, not the time you had in the 401(k). If you already have any Roth IRA that has been open at least five tax years, the rolled-over money is immediately covered because all your Roth IRAs share a single clock. If you’ve never had a Roth IRA before, the five-year period starts fresh on January 1 of the year you open the account and complete the rollover.⁴

When Gains Are Taxed

Any distribution that fails either the five-year rule or the triggering-event requirement is non-qualified. Your original contributions still come out tax-free (you already paid income tax on that money before it went in), but the investment earnings get added to your taxable income for the year and taxed at your ordinary federal rate.⁵ For 2026, federal rates run from 10% to 37%, so a large non-qualified withdrawal can also push you into a higher bracket for the year.⁶

The Pro-Rata Rule

A Roth IRA lets you take out all your contributions first and leave earnings behind. A Roth 401(k) does not. Every non-qualified withdrawal from a Roth 401(k) has to include a proportional share of both contributions and earnings.²

Say your account is 80% contributions and 20% earnings. A $10,000 non-qualified withdrawal is treated as $8,000 in tax-free contributions and $2,000 in taxable earnings.⁷ You cannot cherry-pick just contributions. If the account has grown at all, even a small early withdrawal carries some taxable earnings with it.⁴

The 10% Early Withdrawal Penalty

On top of ordinary income tax, the taxable earnings portion of a non-qualified distribution is generally hit with an additional 10% penalty. The penalty applies only to the earnings included in your gross income, not to the contributions coming out alongside them.⁸

Several exceptions waive the 10% penalty. Note carefully what they do and don’t do: they only remove the penalty. Unless the distribution also meets the full qualified-distribution test, the earnings are still taxed as ordinary income.

Leaving your job during or after the calendar year you turn 55 lets you take penalty-free distributions from that employer’s plan.⁸
Permanent and total disability certified by a physician waives the penalty.
Distributions to a beneficiary or estate after the account holder’s death are penalty-free.
Distributions to a former spouse or dependent under a qualified domestic relations order avoid the penalty.
Unreimbursed medical costs exceeding 7.5% of your adjusted gross income can be withdrawn penalty-free.
A physician’s certification of terminal illness removes the penalty on a 401(k) distribution.³

The SECURE 2.0 Act added two more. A survivor of domestic abuse by a spouse or domestic partner can withdraw the lesser of $10,000 or 50% of the account balance without penalty, for distributions made after December 31, 2023.³ Separately, up to $1,000 per calendar year can be withdrawn for an unforeseeable personal emergency; you have three years to repay it, and you generally cannot take another emergency distribution during that window unless you’ve repaid the previous one.⁹

Employer Matching Contributions Are Taxed Differently

Your Roth 401(k) contributions are after-tax, but employer matching contributions have traditionally gone into a separate pre-tax bucket inside the same plan. That means the entire match, including its growth, is taxed as ordinary income when you withdraw it, exactly like a traditional 401(k) distribution.⁵

Since 2023, the SECURE 2.0 Act has let employers deposit matching contributions directly into the Roth side if they choose to. If your employer offers this option and you elect it, the match is taxable income to you in the year it’s made, but the match and its future growth then follow the same qualified-distribution rules as your own Roth contributions and can come out tax-free.¹⁰ Not every plan has adopted this, so ask your plan administrator how your match is handled.

Using a Roth IRA Rollover to Change the Tax Picture

Rolling your Roth 401(k) into a Roth IRA changes how withdrawals are taxed in one important way: the pro-rata rule goes away. A Roth IRA lets you pull contributions out first and leave the earnings untouched, so you can access money without triggering tax on gains at all.

If you receive a non-qualified distribution from your Roth 401(k) and roll it into a Roth IRA within 60 days, the earnings that would otherwise be taxable ride along in the rollover and stay out of your income for that year. A $14,000 non-qualified distribution made up of $11,000 in contributions and $3,000 in earnings can be shielded entirely by rolling over at least the $3,000 earnings piece (plus any additional amount you choose) into the Roth IRA.⁴

Just remember the clock difference. After a rollover, the Roth IRA’s five-year period is what governs future qualified-distribution treatment. An existing Roth IRA that has already cleared its own five years covers the rolled funds right away; a brand-new Roth IRA starts the clock from scratch.

State Taxes on Roth 401(k) Gains

Federal treatment is only part of the picture. Nine states have no personal income tax, so distributions carry no state tax there regardless of whether they’re qualified. In the rest, qualified Roth 401(k) distributions are generally treated the same as they are federally and come out tax-free at the state level too. Non-qualified earnings may be taxed at your state’s ordinary income rate, though some states offer partial exclusions for retirement income. Rules vary widely, so check your own state before taking a large withdrawal.

1
Office of the Law Revision Counsel. 26 USC 402A – Optional Treatment of Elective Deferrals as Roth Contributions
2
Internal Revenue Service. Retirement Topics – Designated Roth Account
3
Internal Revenue Service. Retirement Topics – Exceptions to Tax on Early Distributions
4
Internal Revenue Service. Retirement Plans FAQs on Designated Roth Accounts
5
Internal Revenue Service. Roth Comparison Chart
6
Internal Revenue Service. IRS Releases Tax Inflation Adjustments for Tax Year 2026
7
Internal Revenue Service. Rollovers of After-Tax Contributions in Retirement Plans
8
Office of the Law Revision Counsel. 26 USC 72 – Annuities; Certain Proceeds of Endowment and Life Insurance Contracts
9
Internal Revenue Service. Notice 2024-55 – Certain Exceptions to the 10 Percent Additional Tax Under Code Section 72(t)
10
Internal Revenue Service. SECURE 2.0 Act Impacts How Businesses Complete Forms W-2