W-2 Box 12 Code W — Employer and employee HSA contributions
Total Health Savings Account contributions — both employer and employee (via pre-tax payroll). Capped at the §223 annual HSA limit for your HDHP coverage tier, plus the $1,000 age-55+ catch-up under §223(b)(3)(B)(ii).
At a glance — Box 12 Code W
- Box name
- Employer and employee HSA contributions
- Reports to
- Must be reconciled on Form 8889, Part I.
- Check against
- Your HSA administrator's year-end statement (Form 5498-SA arrives in May).
What Box 12 Code W means
Code W reports the total HSA contributions made through your employer's cafeteria plan — both what your employer contributed and what you contributed via pre-tax payroll deductions. Direct contributions you made outside payroll (which you deduct above-the-line on Schedule 1, Line 13) are NOT in code W.
You must file Form 8889 any year code W > $0. Form 8889 reconciles your HSA contributions against the annual limit, distributions from the HSA, and your HDHP eligibility month-by-month.
Tax return implications
- Already reduces Box 1 (pre-tax payroll contributions are excluded from wages). Employer contributions are never added to Box 1.
- Does NOT add to Schedule 1 Line 13 — that line is for direct (non-payroll) HSA contributions only.
- Failure to file Form 8889 with code W > 0 causes HSA distributions to be miscategorized as taxable.
Common pitfalls & things to check
- If your spouse also has HSA-eligible coverage, the combined family limit applies — coordinate to avoid excess contributions.
- If you lose HDHP eligibility mid-year (e.g., enroll in Medicare), the HSA limit prorates — code W above that prorated limit is an excess contribution subject to 6% excise tax per year until withdrawn.
- HSA contribution amounts above the year's §223(b) maximum for your coverage tier are excess and must be pulled before the tax filing deadline.
For 2025 returns (filed by April 15, 2026)
- HSA limit (self-only / family)
- $4,300 / $8,550
- HDHP min deductible $1,650 / $3,300 · OOP max $8,300 / $16,600. Age-55+ catch-up adds $1,000 (§223(b)(3)(B)(ii), not indexed).
Values sourced from central tax-year config at build time — update automatically on FY rollover.
Related W-2 boxes
Box 12 — Codes (401(k), HSA, health coverage, ISO, and more)
Up to four labeled amounts (12a–12d) using IRS codes. Common codes: D (401(k) elective deferral), DD (employer health coverage cost), W (employer + employee HSA contributions), AA (Roth 401(k)).
Box 12 Code D — Elective deferrals to a 401(k) plan
Your traditional (pre-tax) 401(k) elective deferrals. Reduces Box 1 dollar-for-dollar, up to the annual §402(g) elective deferral limit (higher with age-50 catch-up and SECURE 2.0 ages-60–63 super-catch-up).
Box 12 Code DD — Cost of employer-sponsored health coverage
The total cost (employer + employee share) of your employer-sponsored group health coverage. Informational only — does not affect your tax.
Box 12 Code E — Elective deferrals to a 403(b) plan
Your traditional (pre-tax) 403(b) elective deferrals. Reduces Box 1 up to the annual §402(g) limit, with a special 15-year catch-up for long-tenured employees of certain nonprofits.
Reconciling your W-2 at tax time? Use the paycheck calculator to verify expected federal, Social Security, and Medicare withholdings on your salary, and the federal income tax calculator to estimate your refund or balance owing before you file.
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Sources
W-2 box definitions per IRS General Instructions for Forms W-2 and W-3 and IRC §6051. Rates and thresholds current for tax year 2025 (file by April 15, 2026); 2026 figures included where published.