What Does Box 12 Code W Mean on a W-2?
HSA contributions (employer + employee pre-tax through payroll) — what it means, whether it's taxable, and what to do with it.
By the Easy Guides Editorial Team · Updated for 2026
Code W in Box 12 of your W-2 means HSA contributions (employer + employee pre-tax through payroll). Tax treatment: Pre-tax (already excluded).
What Code W means
If you also put money into the HSA outside of payroll, you may be able to deduct that extra amount on Form 8889 — but not the Code W amount, which is already tax-free.
Does Code W affect my taxes?
The total contributed to your Health Savings Account through payroll — both your pre-tax contributions and any your employer added. It's already excluded from your Box 1 wages.
Where to find Code W on your W-2
Box 12 has up to four slots — labeled 12a, 12b, 12c, and 12d. Each slot shows a letter code and a dollar amount. The 12a–12d labels are just line numbers; the actual code is the small letter next to the money. So "12a: W 5,000" means Code W with a $5,000 amount. When you file, enter the code and amount exactly as shown.