Updated October 18, 2026. Quick answer: Line 15 is the part of your HSA distributions used to pay qualified medical expenses. Line 16 is what is left after subtracting line 15 from line 14c, and it is the taxable HSA amount that also goes on Schedule 1, line 8f.
Related reading on this site: IRS Publication 502.
What lines 15 and 16 ask for
Line 15 reads “Qualified medical expenses paid using HSA distributions”. Line 16 reads “Taxable HSA distributions. Subtract line 15 from line 14c.” The idea behind both lines comes from the instructions: “Distributions from an HSA used exclusively to pay qualified medical expenses of the account beneficiary, spouse, or dependents are excludable from gross income.”
Line 15: what to include
The instructions say “Only include on line 15 distributions from your HSA that were used to pay you for qualified medical expenses not reimbursed by insurance or other coverage and that you incurred after the HSA was established.” They add “Do not include the distribution of an excess contribution taken out after the due date, including extensions, of your return even if used for qualified medical expenses.”
On whose expenses count: “In general, include on line 15 distributions from all HSAs in 2025 that were used for the qualified medical expenses of:” the instructions list “You and your spouse.”, “All your dependents.” and certain people who would be dependents except for the reasons the instructions list.
The definition of the expenses themselves: “Generally, “qualified medical expenses” for HSA purposes are unreimbursed medical expenses that could otherwise be deducted on Schedule A (Form 1040).” The timing rule is “Expenses incurred before you establish your HSA are not qualified medical expenses.” Keeping receipts is covered on the HSA receipt strategy page.
One more line 15 sentence: “You cannot take a deduction on Schedule A (Form 1040) for any amount you include on line 15.”
Line 16: the taxable amount
The instructions have no separate paragraph headed Line 16, so the form’s own wording carries the rule. The form’s caption reads “Taxable HSA distributions. Subtract line 15 from line 14c. If zero or less, enter -0-.” The general rule behind it is “Any part of a distribution not used to pay qualified medical expenses is includible in gross income and is subject to an additional 20% tax unless an exception applies.” Here is a computed illustration, not an IRS example: suppose line 14c is $3,500 and line 15 is $3,000. Line 16 would then be $3,500 minus $3,000 for a computed result of $500.
Where it goes next
The form tells you “Also, include this amount in the total on Schedule 1 (Form 1040), Part I, line 8f”. That schedule line is explained on the Schedule 1 lines 8d to 8f page and it flows to Form 1040. The additional tax test on line 17 is on the Form 8889 lines 17a and 17b page.
Edition and line numbers
This page reads the 2025 Form 8889 and its 2025 instructions, the current files irs.gov served on 2026-10-18. They are the files for the tax year 2025 return, filed in 2026. The form says “Attach to Form 1040, 1040-SR, or 1040-NR.” Check the tax year printed on the form you are filling in and use the line numbers on that year’s form, because a different year’s form can number or word its lines differently. The form itself is walked through on the Form 8889 page.
Common mistakes
- Including medical bills from before the HSA existed. The instructions say “Expenses incurred before you establish your HSA are not qualified medical expenses.”
- Counting expenses that insurance already paid. Line 15 is limited to expenses “not reimbursed by insurance or other coverage”.
- Also deducting the same bills on Schedule A. The instructions say “You cannot take a deduction on Schedule A (Form 1040) for any amount you include on line 15.”
Related: Form 8889, HSA receipt strategy, Schedule 1 lines 8d to 8f, and Form 1099-SA box 3.
Sources
- Instructions for Form 8889, Health Savings Accounts (2025): https://www.irs.gov/pub/irs-pdf/i8889.pdf
- Form 8889, Health Savings Accounts (HSAs) (2025): https://www.irs.gov/pub/irs-pdf/f8889.pdf
Read from the IRS documents linked above on October 18, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.