Do You Report Roth 401(k) Contributions on Taxes?

Reporting Roth 401(k) contributions on taxes usually means doing nothing at all: the money you defer is already counted in the wages shown on your W-2, and there’s no deduction to claim or line to fill in. Your employer takes care of the paperwork by flagging the contribution with Code AA in Box 12, and the IRS matches that to its records. Reporting only kicks in when something happens to the account: a withdrawal, a rollover, a conversion, a Roth employer match, or an excess deferral that needs to be corrected.

What Your W-2 Already Does for You

Roth 401(k) deferrals come out of your paycheck after tax, so the amount is already sitting inside Box 1 of your W-2 as taxable wages.¹ Your employer separately breaks out the Roth portion in Box 12 with Code AA, which tells the IRS these were designated Roth deferrals into a 401(k) rather than pre-tax contributions or another kind of benefit.²

You don’t enter the Box 12 Code AA figure anywhere on your Form 1040 as a deduction or adjustment. There isn’t one. The reward is on the back end: qualified withdrawals in retirement, including every dollar of investment growth, come out tax-free. All you need to do at filing time is make sure your W-2 is entered accurately into your tax software or handed to your preparer, so the IRS has a clean record of the basis building inside the account.

2026 Contribution Limits to Watch

For 2026, the elective deferral cap across your traditional and Roth 401(k) accounts combined is $24,500. If you’re 50 or older, a $8,000 catch-up brings the ceiling to $32,500. A higher catch-up of $11,250 applies if you turn 60, 61, 62, or 63 during the year, lifting the combined ceiling to $35,750.³ These figures cover your own deferrals only. Employer matching sits outside the limit.

When Reporting Actually Kicks In

Contributions on their own generate no return entries beyond the W-2 your employer already prepared. Reporting becomes your job when one of these happens during the tax year:

You take money out of the account.
You roll the balance to a Roth IRA.
You convert pre-tax 401(k) money into your Roth 401(k) inside the plan.
Your employer deposits a matching contribution directly into your designated Roth account.
You over-contributed and need to pull the excess out.
Your income qualifies you for the Saver’s Credit.

Each of these produces its own form and its own place on Form 1040. Missing the reporting step, even for events that carry no tax, can trigger IRS notices because the agency receives copies of every 1099-R your plan issues.

Distributions and Form 1099-R

Any time you take money out of a Roth 401(k), the plan administrator sends you a Form 1099-R. You report the total distribution from Box 1 on line 5a of Form 1040, and the taxable portion on line 5b.⁴

Box 7 carries the distribution code. Designated Roth 401(k) distributions use Code B, whether or not the payout is qualified.⁵ The signal that a distribution is qualified and fully tax-free is a zero in Box 2a.

A distribution is qualified when two conditions are both met: the designated Roth account has been open for at least five tax years, and you’ve reached age 59½, become disabled, or died.⁶ When both are satisfied, the full amount goes on line 5a, and line 5b shows zero.

Non-Qualified Distributions

Pull money out before meeting those requirements and the earnings portion becomes taxable income. Your own contributions still come back tax-free because you already paid tax on them. The plan uses a pro-rata split based on the ratio of your Roth contributions to the total account balance to figure out how much of each withdrawal is basis and how much is earnings.¹ The taxable earnings show up in Box 2a of the 1099-R, and that number goes on line 5b.

If you’re under 59½, the earnings portion may also carry a 10% early withdrawal penalty.⁷ Exceptions include disability, substantially equal periodic payments, IRS levies, unreimbursed medical expenses above 7.5% of adjusted gross income, distributions under a qualified domestic relations order, and newer SECURE 2.0 exceptions for federally declared disasters (up to $22,000), domestic abuse victims, and qualified birth or adoption expenses (up to $5,000 per child). If Box 7 doesn’t already reflect the right exception code, file Form 5329 to claim it.

Rolling the Account to a Roth IRA

Leaving an employer often means moving the balance to a Roth IRA. How the money travels changes what you report.

Direct Rollovers

In a direct rollover, funds move straight from the 401(k) to the Roth IRA custodian without passing through your hands. Your 1099-R will show Code H in Box 7 and zero in Box 2a, marking a non-taxable transfer.⁵ Enter the total on line 5a of Form 1040, put zero on line 5b, and check the rollover box on line 5c.⁴ The receiving IRA custodian will separately record the incoming rollover in Box 2 of Form 5498 the following year.⁸

Indirect (60-Day) Rollovers

An indirect rollover means the plan writes you a check and you have 60 days to deposit it in a Roth IRA. The plan is required to withhold 20% for federal taxes, even though you plan to complete the rollover.⁹ To keep the whole amount tax-free, you have to replace the withheld 20% from other funds when you make the deposit. If you only deposit the 80% you received, the missing 20% becomes a permanent distribution, potentially taxable on the earnings portion, with the 10% early withdrawal penalty on top if you’re under 59½. This is the reason most rollovers should go direct.

In-Plan Roth Conversions

If your plan allows it, you can convert pre-tax traditional 401(k) money into your Roth 401(k) without leaving the plan. This is called an in-plan Roth rollover, and it’s a taxable event because the money is shifting from tax-deferred to after-tax status.¹⁰ The full converted amount is added to your taxable income for the year.

Your plan issues a 1099-R, and you include the converted amount on line 5b of Form 1040. There’s no 10% penalty on in-plan conversions, but you’ll need cash on hand to cover the extra income tax. That tax is what buys you tax-free growth on the converted balance from that point on.

Roth Employer Matching Contributions

Historically, employer matching contributions always went to a pre-tax account, even when the match was based on Roth deferrals.¹ Section 604 of the SECURE 2.0 Act gave employers the option to deposit matching contributions directly into your designated Roth account. If your plan offers this and you elect it, the match becomes taxable to you in the year it’s allocated.

These Roth matching contributions are reported on a Form 1099-R, not on your W-2, with Code G in Box 7 and the full amount in Boxes 1 and 2a.¹¹ You add that amount to taxable income on your return. Not every plan has adopted the feature, so check with your plan administrator if you’re not sure whether your match is landing pre-tax or Roth.

The Saver’s Credit

If your income is low or moderate, your Roth 401(k) deferrals may qualify you for the Retirement Savings Contributions Credit, better known as the Saver’s Credit. You claim it on Form 8880, listing your elective deferrals (including designated Roth contributions) on Line 2.¹² The maximum contribution counted toward the credit is $2,000 per person, or $4,000 for married filing jointly.

For 2026, the credit phases out entirely above these adjusted gross income limits:³

Married filing jointly: $80,500
Head of household: $60,375
Single or married filing separately: $40,250

Below those ceilings, the credit runs from 10% to 50% of eligible contributions depending on income. At the top rate, a $2,000 Roth 401(k) contribution produces a $1,000 credit against your tax bill. This is one of the few places where Roth 401(k) contributions produce an immediate tax benefit, and it gets missed constantly.

Correcting an Excess Deferral

Contribute more than the $24,500 limit in 2026 and the excess has to come out of the plan by April 15 of the following year. This deadline holds even if you file a tax extension.¹³ The classic setup is switching jobs mid-year and contributing to two 401(k) plans without coordinating.

Corrected on time, the excess and any earnings on it get reported on a 1099-R for the year of the distribution, with the earnings portion taxable. Miss the deadline and the excess is taxed twice: once in the year you contributed it, and again when it eventually leaves the plan. Checking Box 12 Code AA across every W-2 you received is the fastest way to catch an overage before you file.

A Note on Required Minimum Distributions

Section 325 of the SECURE 2.0 Act eliminated required minimum distributions from designated Roth accounts in employer plans, effective for tax years beginning after December 31, 2023.⁶ Starting in 2024, no forced distributions come out of your Roth 401(k) during your lifetime, which means no RMD-driven 1099-R to report and no 25% penalty for missing one.

1
Internal Revenue Service. Retirement Plans FAQs on Designated Roth Accounts
2
Internal Revenue Service. Common Errors on Form W-2 Codes for Retirement Plans
3
Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500
4
Internal Revenue Service. Instructions for Form 1040 (2025)
5
Internal Revenue Service. 2025 Instructions for Forms 1099-R and 5498
6
Office of the Law Revision Counsel. 26 U.S. Code 402A – Optional Treatment of Elective Deferrals as Roth Contributions
7
Internal Revenue Service. Retirement Topics – Exceptions to Tax on Early Distributions
8
Internal Revenue Service. Form 5498 IRA Contribution Information
9
Internal Revenue Service. Rollovers of Retirement Plan and IRA Distributions
10
Internal Revenue Service. Deadline Extended to Add New In-Plan Roth Rollover Provisions
11
Internal Revenue Service. SECURE 2.0 Act Impacts How Businesses Complete Forms W-2
12
Internal Revenue Service. Credit for Qualified Retirement Savings Contributions – Form 8880
13
Internal Revenue Service. Consequences to a Participant Who Makes Excess Deferrals to a 401(k) Plan