HSA Contribution Limit Calculator
Find your maximum HSA contribution for 2025 based on your coverage type, age, and how many months you had HDHP coverage.
How the HSA limit is calculated
The IRS sets separate HSA limits for self-only and family High-Deductible Health Plan coverage — $4,300 and $8,550 for 2025, respectively — and adds a $1,000 catch-up contribution for anyone 55 or older by the end of the year. If you weren't covered by a qualifying HDHP for the full 12 months, the standard rule prorates your limit based on how many months you were covered.
Base family limit: $8,550. Age 55+ catch-up: $1,000. Total: $9,550 for the full year.
Base self-only limit: $4,300 × (8 ÷ 12) = $2,866.67 — prorated for partial-year coverage.
2025 vs. 2024 HSA contribution limits
| Limit | 2024 | 2025 |
|---|---|---|
| Self-only coverage | $4,150 | $4,300 |
| Family coverage | $8,300 | $8,550 |
| Age 55+ catch-up | $1,000 | $1,000 |
The base limits rise most years to account for inflation, but the $1,000 catch-up amount is fixed by law and hasn't been indexed since it was introduced — meaning its relative value slowly shrinks each year the base limit increases.
The "last-month rule" exception
If you're covered by a qualifying HDHP on December 1st of the tax year, a special rule lets you contribute the full annual limit even if you weren't covered the entire year — as long as you remain HDHP-covered through December of the following year (a "testing period"). This calculator applies the standard proration rule; if you qualify for the last-month rule instead, your allowed contribution may be higher than shown here.
Common mistakes when calculating HSA contribution limits
- Forgetting to prorate for partial-year coverage. Unless the last-month rule applies, your limit scales down with fewer months of HDHP coverage.
- Missing the age-55 catch-up. It's a flat $1,000 add-on, separate from and on top of the base limit.
- Assuming both spouses can each claim the full family limit. The family limit is shared between spouses' combined contributions, though each spouse's own catch-up must go into their own account.
Frequently asked questions
What is the HSA contribution limit for 2025?
$4,300 for self-only coverage and $8,550 for family coverage, plus a $1,000 catch-up for those 55 and older.
Do I need to be covered by an HDHP the entire year to contribute the full limit?
No — the limit is normally prorated by months covered, unless the last-month rule applies.
Can both spouses contribute to HSAs if they have family coverage?
Yes, but combined contributions can't exceed the family limit; each spouse's catch-up goes into their own account.
What happens if I contribute more than the HSA limit?
A 6% excise tax applies each year the excess remains, unless withdrawn before the filing deadline.
Can I still contribute after enrolling in Medicare?
No — Medicare enrollment (even just Part A) ends HSA eligibility. Contributions for months after enrollment become excess contributions.
Do employer HSA contributions count toward my limit?
Yes — the IRS limit covers combined employee and employer contributions, so an employer contribution reduces how much you can add yourself.
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Note: Uses 2025 IRS limits; excludes the last-month rule and other special circumstances. Not tax advice. Figures: 2025 IRS Revenue Procedure 2024-25. Last reviewed: September 2026.