To know if your 401(k) is a Roth or traditional account, look at how your contributions are taxed: Roth contributions come out of your paycheck after income tax, while traditional contributions come out before. You can confirm which one you have in four places — your pay stub, your W-2, your plan’s online portal, and your Summary Plan Description. The distinction matters because Roth balances grow and can be withdrawn tax-free under the right conditions, while traditional balances are taxed as ordinary income when you take the money out.1Internal Revenue Service. Roth Comparison Chart
Look at Your Pay Stub First
The deductions section of your most recent pay stub is the quickest answer. Roth contributions usually appear under a label like “Roth,” “Roth 401(k),” or “Designated Roth.” Traditional contributions show up as “Pre-Tax Deferral,” “401(k),” or “Pre-Tax 401(k)” with no Roth wording attached.2Internal Revenue Service. Common Errors on Form W-2 Codes for Retirement Plans
If both a pre-tax line and a Roth line appear, your plan lets you split contributions and is tracking each portion separately. If what you see doesn’t match what you thought you signed up for, raise it with HR or payroll quickly. Misrouted contributions get harder to unwind the longer they sit.
Roth Is Not the Same as After-Tax Voluntary
Some plans offer a third bucket called “after-tax voluntary” or “non-Roth after-tax.” These contributions use money you’ve already been taxed on, just like Roth, but earnings on them are taxed as ordinary income when you withdraw, while qualified Roth earnings are not. After-tax voluntary contributions also have a much higher ceiling — up to the overall plan limit of $72,000 for 2026, versus the $24,500 elective deferral cap that applies to Roth.3Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500 A pay stub line reading “After-Tax” with no “Roth” attached is almost certainly this third category, not a Roth account.
Check Box 12 of Your W-2
Your annual Form W-2 is the most definitive record. Box 12 uses IRS letter codes to report retirement contributions, and two of them tell you the account type:
- Code D means traditional pre-tax elective deferrals to a 401(k).
- Code AA means designated Roth contributions to a 401(k).
A dollar amount next to Code AA confirms you made Roth contributions that year. Only Code D means everything was pre-tax. Both codes together mean you split your contributions across the two account types during the year.4Internal Revenue Service. General Instructions for Forms W-2 and W-3 (2026) Employers are required by federal law to break Roth contributions out under Code AA, so this box is the official tax record of your account type.5Internal Revenue Service. 2026 General Instructions for Forms W-2 and W-3
Log Into Your Plan Portal
Your plan’s recordkeeper — the brokerage or administrator your employer uses — shows your balance broken out by source. Sign in and look for a section called “Account Summary,” “Balance by Source,” or “Investment Details.” A Roth balance appears as its own line, often labeled “Roth Employee Contributions” or “Designated Roth,” separate from any pre-tax balance.
One thing that surprises people: your employer’s matching contributions can show up under a pre-tax label even when your own contributions are Roth. That’s standard. Employers are required to place matching money into a pre-tax account unless the plan has specifically adopted a Roth match feature.6Internal Revenue Service. Retirement Plans FAQs on Designated Roth Accounts The result is a split balance inside a single plan: the employer match portion will be taxed when withdrawn, and your Roth contributions and their earnings will not. Quarterly statements show the same source breakdowns and give you a historical view.
Since late 2022, plans have had the option to let employees designate employer matching and nonelective contributions as Roth.7Internal Revenue Service. SECURE 2.0 Act Impacts How Businesses Complete Forms W-2 If your plan adopted it, you may see a Roth match line you weren’t expecting. Not all plans offer this, so check with your administrator.
Read the Summary Plan Description
The Summary Plan Description is the governing document for your employer’s plan. Federal law requires your employer to give it to every participant and to write it plainly enough for an average employee to understand.8Office of the Law Revision Counsel. 29 U.S. Code 1022 – Summary Plan Description The contributions section states whether the plan offers a Roth elective deferral option alongside, or instead of, traditional pre-tax deferrals.
If Roth isn’t mentioned anywhere in the document, the plan probably only accepts traditional pre-tax contributions. Administrators must update the document when the plan changes, so ask HR for the most recent version. It’s the final word on what your plan allows and on whether you’re currently enrolled in the Roth side.
Why the Answer Matters: The Five-Year Rule
Confirming the account type isn’t just paperwork. Roth 401(k) withdrawals are only fully tax-free if they’re a “qualified distribution,” which means two conditions have to be satisfied at once:
- At least five tax years have passed since January 1 of the year of your first Roth contribution to the plan.
- You are at least 59½, you have become disabled, or the distribution is made to a beneficiary after your death.
Both must be met.9Internal Revenue Service. Retirement Topics – Designated Roth Account The five-year clock starts on the first day of the tax year of your first Roth contribution, not the contribution date. A first Roth contribution in October 2026 starts the clock on January 1, 2026, and it runs through December 31, 2030. If you rolled a Roth balance in from a previous employer’s plan, the clock may start from that earlier plan’s first contribution date.6Internal Revenue Service. Retirement Plans FAQs on Designated Roth Accounts
Withdraw before you meet both tests and your contributions still come out tax-free, because they were taxed going in, but the earnings portion is taxed as ordinary income and may face a 10% early withdrawal penalty. If you’re close to retirement and only now learning your contributions were Roth, this is the number to check.
A New Reason You Might See a Roth Line Appear
Starting with the 2027 tax year, employees age 50 and older who earned more than $150,000 in wages the prior year must make all catch-up contributions on a Roth basis. The rule comes from the SECURE 2.0 Act, and final IRS regulations confirm it applies to taxable years beginning after December 31, 2026. Plans may adopt the rule earlier under a good-faith interpretation, so some employees will see the change on 2026 pay stubs.10Internal Revenue Service. Treasury, IRS Issue Final Regulations on New Roth Catch-Up Rule, Other SECURE 2.0 Act Provisions
For 2026, the standard catch-up limit for ages 50 to 59 and 64 and older is $8,000 on top of the $24,500 regular deferral limit. Ages 60 through 63 get an enhanced catch-up of $11,250.3Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500 If you’re above the $150,000 wage threshold and your plan adopts the Roth catch-up early, those catch-up dollars will be routed to a Roth account automatically even if the rest of your contributions stay pre-tax. A sudden Roth line on your pay stub or portal, without any election on your part, is often this rule taking effect.