What this line means
Your HSA contribution limit based on your HDHP coverage type. For 2025, the limit is $4,300 for self-only coverage and $8,550 for family coverage. 1 This limit applies to the combined total of your contributions (line 1) and employer contributions (line 2). If you had HDHP coverage for only part of the year, you prorate this amount by the number of months you were covered — unless you use the last-month rule. 2
Does this apply to you?
- You were enrolled in an HDHP at any point during 2025
- You need to determine how much you (and your employer combined) can contribute to your HSA
- You changed HDHP coverage type during the year (for example, from self-only to family)
- You became eligible or lost eligibility for an HSA mid-year
Easy to overlook
The last-month rule lets you claim the full annual limit If you had HDHP coverage on December 1, 2025, you can use the full annual contribution limit as if you had coverage all year — even if you were only covered for a few months. The catch: you must stay enrolled in an HDHP through December 31, 2026 (the testing period). If you drop coverage before that, the extra contribution becomes taxable and triggers a 10% penalty. 3 IRS Publication 969 — HSA contribution limits
Mid-year coverage changes require a split calculation If you switched from self-only to family HDHP coverage (or vice versa) during the year, you cannot use a single limit. You calculate the limit for each coverage period separately, prorated by month, and add them together. Filers who switched plans mid-year often use the wrong limit for the full year. 4 IRS Form 8889 instructions — Line 3
Watch out for this
The contribution limit is a ceiling for all contributions combined — yours and your employer’s. If your employer contributed $2,000 and you have self-only coverage ($4,300 limit), you can only contribute $2,300 more on your own. Filers who ignore employer contributions sometimes exceed the limit and owe a 6% excise tax on the excess amount for every year it stays in the account.
Footnotes
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IRS Revenue Procedure 2024-25, HSA Contribution Limits for 2025. https://www.irs.gov/newsroom/irs-provides-tax-inflation-adjustments-for-tax-year-2025 ↩
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IRS Form 8889 Instructions, Line 3. https://www.irs.gov/pub/irs-pdf/i8889.pdf ↩
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IRS Publication 969, Health Savings Accounts, Last-Month Rule. https://www.irs.gov/pub/irs-pdf/p969.pdf ↩
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IRS Form 8889 Instructions, Line 3 — Limitation Chart. https://www.irs.gov/pub/irs-pdf/i8889.pdf ↩