Box 12 on the IRS Form W‑2 is where employers report a variety of compensation and benefit codes that affect your tax return. Each code (e.g., C, D, DD) tells the IRS and you what type of pre‑tax or post‑tax benefit was provided, such as a 401(k) contribution, health‑care premiums, or adoption assistance.
What Is Box 12 on the W‑2 Form?
Box 12 can contain multiple entries, each consisting of a one‑ or two‑letter code followed by an amount. The most common codes include:
- C – Taxable cost of group-term life insurance over $50,000
- D – Elective deferrals to a 401(k) plan
- DD – Cost of employer‑provided health coverage (not taxable)
- E – Elective deferrals to a 403(b) plan
- W – Employer contributions to a Health Savings Account (HSA)
How to Complete Box 12 Using Formize
Instead of downloading the PDF and opening a separate editor, simply click the "Fill out this form" button on this page. The Formize PDF Filler app loads directly in your browser, letting you type into each field, including every Box 12 entry.
Common Mistakes When Filling Box 12
- Entering the wrong code – double‑check your employer’s payroll summary.
- Leaving the amount blank – even $0 must be entered if the code appears.
- Mixing up pre‑tax and post‑tax amounts – this can affect your AGI.
Where to Submit Your Completed W‑2
After you finish, download the completed PDF and attach it to your federal tax return (e.g., when e‑filing) or provide a hard copy to your tax preparer. The form is also accepted by most state tax agencies.
Download the Fillable PDF Instantly
Click the button below to launch the Formize filler, complete Box 12, then save or print your W‑2 for tax filing.