How this calculator works
Tax year: 2026, United States. The annual HSA limit is $4,400 for self-only coverage and $8,750 for family coverage. A $1,000 catch-up applies for each eligible person aged 55 or older. Employer contributions count toward the same limit as your own, so the two are added before the room is calculated. The limit follows the coverage you have for the month, and family coverage lets either spouse own the account. The model assumes full-year eligibility and leaves out the last-month rule, the married-individual split when both spouses have family coverage, mid-year coverage changes, the requirement to stop contributing once enrolled in Medicare, and the tax on excess contributions. It also does not test whether the health plan qualifies as a high-deductible plan.
Formula
Limit = 4,400 for self-only coverage or 8,750 for family coverage. Catch-up = 1,000 when age is 55 or older. Total limit = limit + catch-up. Remaining room = max(0, total limit - employer contribution - your contribution). Excess = max(0, employer contribution + your contribution - total limit).
Worked example
Family coverage at age 45 with a $2,000 employer contribution and $5,000 of your own gives a limit of $8,750. Contributions of $7,000 leave $1,750 of room. At age 57 with self-only coverage, the limit is $4,400 plus the $1,000 catch-up, or $5,400.
Frequently asked questions
Do employer contributions count toward the limit?
Yes. Employer and employee contributions share one annual limit. Money your employer adds reduces the amount you can contribute yourself.
Who can make the catch-up contribution?
Anyone aged 55 or older who is otherwise eligible to contribute. A married couple with two eligible spouses aged 55 or older can each add $1,000 to their own accounts.
Can I contribute for a partial year?
The limit is normally prorated by the months you are eligible. The special last-month rule can allow the full limit if you are eligible on 1 December and stay eligible through the following year. This calculator assumes full-year eligibility.
What happens if I contribute too much?
Excess contributions are taxed each year until they are withdrawn, and earnings on them are also taxed. Withdraw the excess and its earnings before the tax filing deadline to avoid the charge.