Updated October 18, 2026. Quick answer: Line 6 carries your line 5 limit, or your share of it if you and your spouse have separate HSAs and family coverage. Line 7 is the additional contribution amount for people age 55 or older who are married with family coverage. Line 8 adds lines 6 and 7 to give your total contribution limit.
What lines 6, 7 and 8 ask for
Line 6 reads “Enter the amount from line 5. But if you and your spouse each have separate HSAs and had family coverage under an HDHP at any time during 2025, see the instructions for the amount to enter”. Line 7 reads “If you were age 55 or older at the end of 2025, married, and you or your spouse had family coverage under an HDHP at any time during 2025, enter your additional contribution amount.” Line 8 reads “Add lines 6 and 7.”
Line 6: splitting between spouses
For spouses with separate HSAs the instructions start “Spouses who have separate HSAs and had family coverage under an HDHP at any time during 2025, use the following rules to figure the amount on line 6.” If family coverage applied in every month: “divide the amount on line 5 equally between you and your spouse, unless you both agree on a different allocation (such as allocating nothing to one spouse).” “Enter your allocable share on line 6.”
If family coverage did not apply in every month, the instructions give four steps. Step 1 is “Refigure the contribution limit that would have been entered on line 5 if you had entered on line 3 the total of the worksheet amounts only for the months you were treated as having family coverage.” Step 2 is “Divide the refigured contribution limit from Step 1 equally between you and your spouse, unless you both agree on a different allocation (such as allocating nothing to one spouse).” Step 3 is “Subtract the part of the contribution limit allocated to your spouse in Step 2 from the amount determined in Step 1.” Step 4 is “Determine any other contribution limits that apply for the tax year and add that amount to the result in Step 3. Enter the total on line 6.”
Line 7: the additional contribution amount
The instructions say “If, at the end of 2025, you were age 55 or older and married, use the Additional Contribution Amount Worksheet (in these instructions) if both of the following apply.” The first condition is “You or your spouse had family coverage under an HDHP and were, or were considered to be, an eligible individual on the first day of the month.” The second is “You were not enrolled in Medicare for the month.”
The instructions finish with “If items (1) and (2) apply to all months during 2025, enter $1,000 on line 7.” Otherwise the worksheet works month by month. The unmarried and self-only case is handled on line 3 instead, as explained on the Form 8889 lines 3, 4 and 5 page.
Where the number comes from (line 8)
Line 8 is a straight sum of lines 6 and 7, as the form words it. The instructions have no separate paragraph headed Line 8, so the form’s own wording carries the rule. Here is a computed illustration, not an IRS example: suppose line 6 is $4,000 and line 7 is $1,000. Line 8 would then be $4,000 plus $1,000 for a computed result of $5,000. The combined result is your limit before employer contributions are taken out on the Form 8889 lines 9 to 13 page.
Where it goes next
Line 8 is used in line 12, which the form words as “Subtract line 11 from line 8. If zero or less, enter -0-”. The instructions also refer to line 8 as your limitation: “Excess employer contributions are the excess, if any, of your employer’s contributions over your limitation on line 8.” Spouses with separate HSAs each file their own form, a point covered on the HSA catch-up for both spouses 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
- Splitting the family limit when you share a single HSA. The line 6 split applies to “Spouses who have separate HSAs and had family coverage under an HDHP at any time during 2025”.
- Entering the age 55 amount on line 7 when you were enrolled in Medicare. One of the two conditions is “You were not enrolled in Medicare for the month.”
- Ignoring an agreed split. The instructions allow “unless you both agree on a different allocation (such as allocating nothing to one spouse).”
Related: Form 8889, HSA catch-up for both spouses, HSA contribution limits, and HSA and the Medicare six month lookback.
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.