Does a W-2 Show 401(k) Contributions? Box 12 Codes and Box 13

Yes, a W-2 does show your 401(k) contributions. Look at Box 12. Pre-tax 401(k) deferrals appear next to Code D, and Roth 401(k) deferrals appear next to Code AA. The dollar amount printed alongside the code is the total you contributed through that employer during the calendar year.

Where to Find the Number on the Form

Box 12 is the section of the W-2 set aside for deferred compensation and certain special benefits. It has four sub-sections, each holding a one- or two-letter code paired with a dollar amount. Your 401(k) contributions sit here rather than being folded into the main wage totals, which lets the IRS see exactly how much you deferred into a retirement account versus how much counted as taxable pay.¹

If you contribute to more than one type of tax-advantaged account through work, Box 12 can fill up quickly. Health Savings Account contributions (Code W) and the total cost of your employer-sponsored health coverage (Code DD) share the same four slots as retirement deferrals.² Code DD is informational only. It isn’t money you put into a retirement plan and it isn’t taxable.³

What Each Retirement Code Means

Different retirement plans use different codes. If you have a 401(k), the two you’ll actually see are D and AA. The others help you recognize a miscoding.

Code D: pre-tax 401(k) contributions, including SIMPLE 401(k) plans. This is the standard entry for a traditional 401(k).
Code AA: Roth 401(k) contributions. These come from after-tax dollars, so they don’t cut your current taxable income, but qualified withdrawals in retirement are tax-free.
Code E: pre-tax 403(b) contributions, common at schools, hospitals, and nonprofits.
Code BB: Roth 403(b) contributions.
Code S: SIMPLE IRA contributions. A common employer mistake is using Code S for a SIMPLE 401(k), which actually belongs under Code D.
Code G: 457(b) deferred compensation, typically for government employees.
Code EE: Roth contributions to a governmental 457(b) plan.

The IRS has flagged coding mismatches as a frequent employer error, including 403(b) deferrals reported under Code D. If you know what kind of plan you’re in and the code doesn’t line up, raise it with payroll.²

For 2026, the base elective deferral limit is $24,500, up from $23,500 in 2025. Your combined Code D and Code AA amounts should fall at or below that unless you qualify for a catch-up: an extra $8,000 at age 50 and older, or $11,250 for ages 60 through 63 under the SECURE 2.0 Act.⁴

How Your Contribution Changes the Wage Boxes

Reading Box 12 next to the wage boxes shows exactly how the 401(k) affected your tax picture.

Pre-tax contributions (Code D) are excluded from Box 1, which is your federal taxable wages. That’s the immediate benefit of a traditional 401(k): every dollar deferred shrinks the income the IRS taxes for the year. But those same contributions are still included in Box 3 (Social Security wages) and Box 5 (Medicare wages), because FICA taxes apply to your gross pay before the 401(k) deduction. Expect Box 1 to be noticeably lower than Boxes 3 and 5.¹

Roth contributions (Code AA) don’t reduce any wage box. You already paid income tax on those dollars, so they stay in Box 1, Box 3, and Box 5. The Code AA line simply records the amount that went into the Roth side of the plan.⁵

A quick check: subtract your Code D amount from Box 3, and the result should come close to Box 1. Other pre-tax deductions like health insurance premiums account for small gaps. A wide gap points to a reporting error.

The Employer Match Is Not on Your W-2

Box 12 tracks your elective deferrals only. Employer matching contributions do not appear there. Matches are reported to the IRS through the plan’s Form 5500 filing, not through your W-2. Some employers list the match in Box 14 (labeled “Other”), but that’s voluntary and Box 14 has no standardized codes.¹

For the total that actually landed in your account, including the match, check the plan’s year-end statement or the recordkeeper’s online portal.

What the Box 13 Checkbox Signals

Below the wage boxes, Box 13 has a small “Retirement plan” checkbox. Your employer checks it if you were an active participant in a qualified plan at any point in the year, which covers 401(k), 403(b), SEP, SIMPLE, and most government pension plans.²

The check matters for anyone also thinking about a traditional IRA. Once the box is checked, the deduction for traditional IRA contributions phases out above certain income levels. For 2026:

Single filers covered by a workplace plan: $81,000 to $91,000 modified adjusted gross income.
Married filing jointly, contributing spouse covered: $129,000 to $149,000.
Married filing jointly, contributing spouse not covered but the other spouse is: $242,000 to $252,000.
Married filing separately, covered by a plan: $0 to $10,000.

Inside the range, the deduction is reduced proportionally. Above the top of the range, no deduction. If Box 13 is unchecked, these phase-outs don’t apply regardless of income.⁴

If the Number Looks Wrong

Compare the Box 12 amount to your final pay stub of the year or your 401(k) plan statement. If the figure doesn’t match, or if the code is wrong for your plan type, contact your employer’s payroll department. Only your employer can issue a corrected Form W-2c.⁶

If payroll hasn’t fixed it by the end of February, you can call the IRS at 800-829-1040 or visit a Taxpayer Assistance Center. The IRS will send your employer a letter requesting the correction within 10 days and give you instructions for filing Form 4852, a substitute W-2 you complete using pay stubs and personal records so you can still file on time.⁷ If a corrected W-2c later shows different numbers than your Form 4852 estimates, you’ll need to reconcile with an amended return on Form 1040-X.

1
Internal Revenue Service. Retirement Plan FAQs Regarding Contributions
2
Internal Revenue Service. Common Errors on Form W-2 Codes for Retirement Plans
3
Internal Revenue Service. Form W-2 Reporting of Employer-Sponsored Health Coverage
4
Internal Revenue Service. 401(k) Limit Increases to $24,500 for 2026, IRA Limit Increases to $7,500
5
Internal Revenue Service. 2026 General Instructions for Forms W-2 and W-3
6
Internal Revenue Service. About Form W-2 C, Corrected Wage and Tax Statements
7
Internal Revenue Service. If You Don’t Get a W-2 or Your W-2 Is Wrong