- HSA contribution limit
- The most that can go into a Health Savings Account for one tax year, counting your deposits and your employer’s together. For 2026 the limit is $4,400 for self-only coverage and $8,750 for family coverage (IRS Rev. Proc. 2025-19). This calculator starts from that base limit, adds any catch-up, and subtracts what is already in.
- Health Savings Account (HSA)
- A tax-advantaged account paired with a high-deductible health plan. Contributions are tax-deductible or made pre-tax through payroll, growth is not taxed, and withdrawals for qualified medical expenses are tax-free. Unused money rolls over from year to year and stays with you if you change jobs or health plans.
- High-deductible health plan (HDHP)
- A health plan with a higher deductible and out-of-pocket structure that meets IRS requirements, which is what makes you eligible to contribute to an HSA. The IRS sets the minimum deductible and maximum out-of-pocket amounts each year. Whether your HDHP covers only you or your family determines which base limit this calculator uses.
- Self-only vs. family coverage
- The coverage tier of your HDHP. Self-only covers just the account holder; family covers the holder plus at least one other person. The tier sets your base limit — $4,400 self-only or $8,750 family for 2026 (IRS). If coverage changes mid-year, the limit is generally figured month by month for each tier.
- Catch-up contribution (55+)
- An extra amount account holders can add once they are 55 or older by the end of the tax year: $1,000, fixed by statute (IRS Pub. 969, applies for 2026). It is added on top of the base limit. If both spouses are 55+, each needs their own HSA to make a catch-up; it cannot be doubled in one account.
- Employer contributions
- Money your employer deposits into your HSA, including amounts routed through a cafeteria plan. They count toward the same annual limit as your own deposits, so this calculator treats them as already contributed. Leaving them out is a common way to overshoot the limit and end up with an excess contribution to correct.
- Prorated limit
- When you are HSA-eligible for only part of the year, the limit is generally reduced to the months you had HDHP coverage — for example, 6 eligible months allows about half the annual amount. An exception, the last-month rule, can allow the full limit but requires staying eligible through a testing period afterward.
- Medicare enrollment
- Once you enroll in any part of Medicare, you can no longer contribute to an HSA; your limit drops to $0 from that month on. You can still spend the existing balance on qualified expenses. Medicare Part A enrollment can be backdated when you apply after becoming eligible, which may make recent contributions excess.
- Contribution deadline
- Contributions for a tax year can be made up to that year’s federal filing deadline, usually in April of the following year, without extensions. That is why this calculator lets you spread the remaining amount over the months left, which may run past December. Designate prior-year deposits with your HSA custodian.