HSA limits · proration · IRS Pub 969
How much can you put in your HSA this year?
If you did not have HDHP coverage for all twelve months, your HSA limit is prorated. Tell HSAProrate your coverage and eligible months and it gives you the exact figure — including the age-55 catch-up and the last-month rule, with a clear warning about the testing-period clawback.
- Prorated base limit$4,400
- Total you can contribute$4,400
Educational estimate, not tax advice. Limits are combined across you and your employer; verify the current figures with IRS Publication 969 / Form 8889 or a tax professional.
HSA & HDHP figures for 2026 and 2025
| Item | 2026 | 2025 |
|---|---|---|
| Contribution limit — self-only | $4,400 | $4,300 |
| Contribution limit — family | $8,750 | $8,550 |
| Age-55+ catch-up | $1,000 | $1,000 |
| HDHP min deductible — self / family | $1,700 / $3,400 | $1,650 / $3,300 |
| HDHP out-of-pocket max — self / family | $8,500 / $17,000 | $8,300 / $16,600 |
Figures from the IRS annual revenue procedures. The catch-up is fixed at $1,000 by statute (not inflation-indexed). Always confirm the current year against IRS Publication 969.
How the math works
- Eligibility is monthly: you count a month if you had HDHP coverage on its 1st day with no disqualifying coverage.
- Prorated limit = annual limit x eligible months / 12; the $1,000 catch-up (age 55+) prorates the same way.
- Last-month rule: eligible on December 1 lets you contribute the full annual limit — but starts a testing period (Dec 1 to Dec 31 of next year).
- Fail the testing period and the amount above your prorated limit becomes taxable income plus a 10% additional tax.
HSAProrate calculates one person at a time. For married couples with family coverage, the family limit is shared between spouses, but each age-55 catch-up must go into that spouse’s own HSA.
Questions
How is the HSA contribution limit prorated?
You are HSA-eligible for a month if you have qualifying HDHP coverage on the first day of that month and no disqualifying coverage. If you are not eligible all year, your base limit is the annual amount times the number of eligible months divided by 12. The age-55+ catch-up ($1,000) is prorated the same way, and HSAProrate does that math for both.
What is the last-month rule?
If you are HSA-eligible on December 1, the last-month rule lets you contribute the full annual limit for that December coverage type, even if you were not eligible earlier in the year. It is optional — you can also just contribute the prorated amount with no strings attached.
What is the testing period (the 13-month trap)?
If you use the last-month rule, you must stay HSA-eligible for the entire following calendar year — the testing period runs from December 1 of the contribution year through December 31 of the next year. If you lose eligibility during it (other than death or disability), the extra amount you contributed above the prorated limit is added back to your taxable income and hit with an additional 10% tax. HSAProrate shows exactly how much is at risk.
Do employer contributions count against my limit?
Yes. The IRS limit is the combined total of what you, your employer, and anyone else put into your HSA for the year. Enter what has already gone in (including employer and payroll contributions) to see how much room you have left.
I have family coverage and so does my spouse — who gets the catch-up?
The family contribution limit is shared and can be split between spouses in any way you agree. But each $1,000 age-55+ catch-up must go into that spouse's own HSA — you cannot combine both catch-ups in one account. This tool calculates one person's figures at a time.
When is the deadline to contribute?
You can make HSA contributions for a tax year up to the federal tax-filing deadline of the following April (without extensions) — for 2026 that is April 15, 2027. Just tell your HSA custodian which tax year the contribution is for.