Enter the numbers from your Form W-2 (box 12, code W), Form 1099-SA and your medical receipts. The calculator figures your HSA contribution limit, your HSA deduction, any taxable distributions, the 20% additional tax and excess contributions, and shows every line of Form 8889 and where it goes on your return.
Tax Years 2025–2026The annual limit is $4,300 self-only / $8,550 family for 2025 and $4,400 / $8,750 for 2026, plus $1,000 if you are 55 or older at the end of the year. If you were not eligible all year, the limit is figured month by month: the yearly amount × months eligible ÷ 12 (the Line 3 Limitation Chart). If you were eligible on December 1, the last-month rule lets you use the full-year limit, provided you stay eligible through December 31 of the following year. Married people with family coverage share one family limit (line 6); a spouse's $1,000 catch-up is figured on line 7 and must go into that spouse's own HSA. Everything your employer put in — including your own pre-tax payroll deductions, shown in W-2 box 12, code W — reduces the room left for deductible contributions (lines 9–12). Your HSA deduction (line 13) is the smaller of what you contributed yourself (line 2) and that remaining room.
Line 14a is the total of box 1 of all your Forms 1099-SA. Money spent on qualified medical expenses (line 15) is tax-free. Anything else is taxable income (line 16, to Schedule 1, line 8f) and, unless you were 65 or older, disabled, or the distribution was made after death, also carries a 20% additional tax (line 17b, to Schedule 2, line 17c).
Contributions above your limit are not deductible. If you leave them in the account, a 6% excise tax applies every year they stay there (Form 5329, Part VII; the tax is limited to 6% of the account value at year end). You avoid it by withdrawing the excess and its earnings by the due date of your return, including extensions; the earnings are taxable as other income.
Coverage that switched between self-only and family during the year, figuring the line 18 amount for a failed testing period, Archer MSAs and Medicare Advantage MSAs, inherited HSAs, deemed distributions (prohibited transactions, using the HSA as loan security), and employer contributions that belong to a different year (Employer Contribution Worksheet). State taxes are not included; Florida has no income tax, but a few states (for example, California and New Jersey) tax HSAs.
New to HSAs? Read our short guide: HSA Basics: Limits, Deadlines and Form 8889.
This calculator gives an estimate for planning and checking purposes only, not a final calculation. It follows the Form 8889 instructions described above and does not cover every situation (mixed coverage during the year, testing-period recapture, inherited accounts, state taxes). Your tax software or the official IRS form governs. Consult a tax professional before filing. Calculator created October 11, 2026 — figures reflect IRS guidance current as of that date.
