HSA Calculator
A Health Savings Account (HSA) offers a triple tax advantage: contributions are tax-deductible, investment growth is tax-free, and withdrawals for qualified medical expenses are tax-free. HSAs are available only to people enrolled in a high-deductible health plan (HDHP). Unlike flexible spending accounts, HSA balances roll over indefinitely with no use-it-or-lose-it deadline, making them a powerful long-term retirement savings tool. This calculator shows your annual tax savings based on your contribution amount and marginal tax rate, then projects your HSA balance over your chosen time horizon at an assumed investment return. The tool includes the 2025 IRS contribution limits, age 55+ catch-up provisions, and lets you model the impact of annual medical withdrawals. It also compares your HSA balance to what you'd accumulate in a taxable account, illustrating the tax advantage of HSA investing over decades.
Contributing $4,300 per year to an HSA saves approximately $1,161 in taxes annually. Over 20 years, your projected HSA balance is $103,000 (at 6% annual return).
How to read the badges beside each field: Official figures come from a cited authority; Regional average and Illustrative assumption values are editable placeholders, so replace them with your own figure before you rely on the result.
2025 HSA contribution limits
The IRS sets HSA contribution limits annually. For 2025, per IRS Rev Proc 2024-25:
| Coverage type | Annual contribution limit | With age 55+ catch-up |
|---|---|---|
| Self-only HDHP | $4,300 | $5,300 |
| Family HDHP | $8,550 | $9,550 |
The minimum HDHP deductible for 2025 is $1,650 (self-only) or $3,300 (family). The out-of-pocket maximum is $8,300 (self-only) or $16,600 (family).
How the HSA growth is calculated
The projected balance uses the standard future value formula for a series of regular contributions, as described in IRS Publication 969 for illustrative purposes.
Net annual contribution = annual contribution - annual medical withdrawals
FV = existingBalance x (1 + r)^n + netContrib x ((1 + r)^n - 1) / r
where r = annual return rate (decimal), n = years
Annual tax saved = contribution x (federal rate + state rate) / 100
The taxable account comparison assumes the same net contribution amount invested in a taxable account, with returns taxed annually at the combined marginal rate. The difference shows the value of the HSA's tax-free growth.
The triple tax advantage
Per IRS Publication 969, an HSA provides three tax benefits that no other account type combines:
- Contributions: Pre-tax if made through payroll, or tax-deductible on Form 8889 if made directly.
- Growth: Interest and investment gains inside the HSA are not taxed.
- Qualified withdrawals: Withdrawals for qualified medical expenses are completely tax-free at any age.
For comparison, a traditional IRA only provides benefits 1 and 2 (not the tax-free withdrawal). A Roth IRA provides benefits 2 and 3 but contributions are post-tax. The HSA is the only account with all three.
HSA as a long-term retirement strategy
Many financial planners recommend maximising your HSA contribution before contributing above the employer match to a 401(k). This is because the HSA's triple tax advantage generally exceeds the benefit of a traditional 401(k) (pre-tax contributions and tax-deferred growth, but taxable withdrawals).
A particularly effective strategy is to pay current medical expenses out of pocket and preserve receipts, letting the HSA grow tax-free. You can reimburse yourself for past qualified expenses at any time in the future, effectively converting the HSA into a tax-free source of cash while the balance continues to compound. There is no deadline on reimbursing past expenses as long as the expense occurred after the HSA was established.
After age 65, HSA funds can be used for Medicare premiums, Medicare Advantage premiums, and other healthcare costs that continue to be tax-free, or for any other purpose subject to ordinary income tax (no penalty).
Where the simple HSA math misleads
The federal side of this calculator is sound, but the field where people most often overstate their savings is the state income tax rate. Most states mirror the federal HSA deduction, yet California and New Jersey do not: both tax your contributions as income and tax the account's earnings each year. A California resident who accepts the 5% default here would see about $215 of annual state tax saved that the Franchise Tax Board does not actually allow. If you live in either state, set the state rate to 0 so the projection reflects federal savings only.
The catch-up contribution hides a trap the calculator cannot see. The extra $1,000 allowed at age 55 is per person and must go into that person's own HSA, so a married couple who are both 55 or older cannot stack $2,000 into a single account. The family limit ($8,550 for 2025, rising to $8,750 for 2026) is one household cap split between spouses, not a number you double. Couples who each hold an account should run the tool twice, once for each spouse's share.
One timing point the projection assumes away: enrolling in Medicare ends HSA eligibility, and Part A backdates up to six months when you claim it after age 65. Stop contributing at least six months before you file for Medicare or Social Security, or the excess is hit with a 6% excise tax.
HSA calculator: frequently asked questions
What is a Health Savings Account (HSA)?
A Health Savings Account is a tax-advantaged savings account available to people enrolled in a High Deductible Health Plan (HDHP). HSAs have a triple tax advantage: contributions are pre-tax (or tax-deductible if made after-tax), investment growth is tax-free, and withdrawals for qualified medical expenses are also tax-free. Unused funds roll over each year with no 'use-it-or-lose-it' deadline. The rules are set out in IRS Publication 969.
Who qualifies for an HSA?
To contribute to an HSA you must be enrolled in an IRS-qualified High Deductible Health Plan, not be covered by another non-HDHP health plan, not be enrolled in Medicare, and not be claimed as a dependent on someone else's tax return. For 2025, an HDHP must have a minimum deductible of $1,650 (self-only) or $3,300 (family) and an out-of-pocket maximum of no more than $8,300 (self-only) or $16,600 (family), per IRS Rev Proc 2024-25.
Can I use my HSA for non-medical expenses after age 65?
Yes. After age 65, you can withdraw HSA funds for any purpose. Non-medical withdrawals are subject to ordinary income tax, similar to a traditional IRA, but there is no 10% penalty. Before age 65, non-qualified withdrawals are subject to income tax plus a 20% penalty. This makes an HSA a particularly powerful retirement savings vehicle: use funds tax-free for medical expenses at any age, or treat the account like an IRA after 65.
Do HSA funds roll over from year to year?
Yes. Unlike a Flexible Spending Account (FSA), there is no use-it-or-lose-it rule for HSAs. Any balance remaining at year-end carries over indefinitely. This allows you to build a substantial investment balance over many years, particularly if you pay current medical expenses out of pocket and let the HSA grow.
Can I invest my HSA balance?
Yes, most HSA custodians allow you to invest your balance in mutual funds, ETFs, or other options once your balance exceeds a threshold (often $1,000). Investment growth inside the HSA is tax-free, which is what makes long-term HSA accumulation so powerful. Compare HSA custodian fees and investment options carefully, as they vary widely.
What are the 2025 HSA contribution limits?
For 2025, the IRS limit is $4,300 for self-only HDHP coverage and $8,550 for family coverage (IRS Rev Proc 2024-25). If you are aged 55 or older, you can contribute an additional $1,000 catch-up amount. These limits include both your own contributions and any employer contributions. Contributions above the limit are subject to a 6% excise tax.
Official sources
- 2025 HSA limits: IRS Rev Proc 2024-25.
- HSA rules, triple tax advantage: IRS Publication 969, Health Savings Accounts and Other Tax-Favored Health Plans.
Reviewed by the CalculatorHub team, edited by James Graham, 12 June 2026. See our methodology. General information, not financial advice.