What Is Code AA on W-2 Form Guide? – If you’ve received your 2025 Form W-2 and noticed “AA” followed by a dollar amount in Box 12, you’re not alone. Many U.S. employees wonder what Code AA means and how it affects their taxes. This comprehensive guide explains everything you need to know about Code AA on W-2 Form, based on the latest IRS instructions for Forms W-2 and W-3 (2026).
What Is Code AA on the W-2 Form?
Code AA in Box 12 of your Form W-2 reports designated Roth contributions under a section 401(k) plan. These are after-tax employee contributions to a Roth 401(k) account offered by your employer.
Unlike pre-tax traditional 401(k) contributions (reported with Code D), Roth contributions are made with money that has already been taxed. Your employer must separately report these amounts using Code AA so the IRS can track them correctly for future tax-free qualified distributions.
Where to Locate Code AA on Your W-2?
Code AA appears in Box 12 of Form W-2, which has up to four lines labeled 12a, 12b, 12c, and 12d. You’ll see:
- The code “AA” in one of the letter boxes
- The dollar amount of your designated Roth 401(k) contributions right next to it
Box 12 may also show other codes (such as D for traditional 401(k) deferrals or DD for health coverage cost). Code AA is only for Roth 401(k) contributions—it is not used for elective deferrals under Code D.
Understanding Designated Roth Contributions (Code AA)
Designated Roth contributions let you save for retirement with after-tax dollars. Key facts:
- Contributions are included in your taxable wages (Box 1), Social Security wages (Box 3), and Medicare wages (Box 5).
- They are subject to federal income tax withholding, Social Security, and Medicare taxes (and railroad retirement taxes if applicable).
- Earnings grow tax-free, and qualified withdrawals (generally after age 59½ and a 5-year holding period) are entirely tax-free.
Your employer may also report contributions to a pension-linked emergency savings account (a special Roth account) using Code AA in Box 12.
Code AA vs. Other Common Box 12 Codes
Many taxpayers confuse Code AA with similar codes. Here’s a quick comparison:
| Code | Type of Contribution | Included in Box 1 (Taxable Wages)? | Tax Treatment |
|---|---|---|---|
| AA | Roth 401(k) | Yes | After-tax; tax-free qualified distributions |
| D | Traditional 401(k) | No | Pre-tax; taxed on withdrawal |
| BB | Roth 403(b) | Yes | After-tax Roth |
| EE | Roth governmental 457(b) | Yes | After-tax Roth |
Important: Do not report Code AA amounts as pre-tax deferrals. The IRS requires separate tracking.
Tax Implications of W-2 Code AA
Because Code AA amounts are already included in Box 1, they increase your taxable income for the year. However, this also means:
- You’ve already paid income taxes on the contribution.
- The money and its earnings can grow tax-free in your Roth 401(k).
- You may qualify for the Saver’s Credit (Retirement Savings Contributions Credit) on Form 8880 if your income is within limits. Tax software automatically considers Box 12 Code AA amounts for this credit.
Code AA does not reduce your current-year taxable wages like traditional 401(k) contributions do.
How Code AA Affects Your 2025 Tax Return?
When filing your 2025 federal tax return in 2026:
- No additional reporting is usually required for the contribution itself—it’s already reflected in Box 1.
- Enter the full W-2 (including Box 12 Code AA) into your tax software or Form 1040.
- Tax programs like TurboTax or H&R Block automatically handle Code AA correctly for the Saver’s Credit and Roth account tracking.
- Keep your W-2 for your records; you’ll need contribution basis information when you eventually withdraw from the Roth 401(k).
Reporting W-2 Code AA in Tax Software or Paper Forms
In tax software:
- Enter your W-2 exactly as it appears.
- When prompted for Box 12, select or type “AA” and enter the amount.
- The software will use it for credit calculations and future Roth tracking.
On paper Form 1040:
- Simply attach Copy B of your W-2. No separate line exists for Code AA on the 1040 itself.
Common Mistakes and Misconceptions About Code AA
- Mistake: Thinking Code AA reduces your taxable income like Code D.
Reality: It is after-tax, so it’s already in Box 1. - Mistake: Confusing it with uncollected taxes (Codes A or B).
Reality: Code AA is strictly for Roth 401(k) contributions. - Misconception: “I can deduct it again.”
Reality: No double-dipping—the tax was already paid.
Always double-check your W-2 against your final paystub.
Why Employers Report Code AA on Form W-2?
Section 402A of the Internal Revenue Code requires employers to separately report designated Roth contributions. This helps the IRS:
- Verify contribution limits across plans.
- Track your Roth basis for tax-free withdrawals.
- Ensure compliance with retirement plan rules.
Employers must also check the “Retirement plan” box in Box 13 if you participated in any 401(k), including Roth.
Frequently Asked Questions About Code AA on W-2
Q: Is Code AA taxable income?
A: Yes—the amount is already included in Box 1 wages and taxed in the year contributed.
Q: Does Code AA count toward my 401(k) contribution limit?
A: Yes. Combined traditional (Code D) and Roth (Code AA) contributions cannot exceed the annual limit (plus any catch-up if age 50+). Check IRS.gov for the exact 2025 limit.
Q: What if I have both Code D and Code AA?
A: That’s common and allowed. Report both separately in Box 12.
Q: Will Code AA affect my Social Security or Medicare taxes?
A: Yes—it is included in Boxes 3 and 5, so FICA taxes were withheld.
Final Tips for USA Taxpayers
- Review your W-2 carefully before filing.
- Save all retirement plan statements—they’ll help when you take distributions.
- Consult a tax professional or use reputable tax software if your situation includes multiple jobs, high income, or other complex factors.
- For the most current limits and rules, visit IRS.gov and search “Form W-2 instructions” or Publication 525.
Understanding Code AA on your W-2 Form helps you maximize Roth 401(k) benefits and avoid filing errors. If your W-2 shows Code AA, you’re building tax-free retirement savings—congratulations on planning ahead! For personalized advice, speak with a qualified tax advisor or your plan administrator. Always refer to the official IRS General Instructions for Forms W-2 and W-3 for the latest details.