HSA Growth Calculator
Project how your HSA contributions could grow tax-free, and see how much you save in income tax and FICA by contributing through payroll.
Last reviewed
Contributing $8,750/year to an HSA and investing it at 6% for 25 years grows to about $480,064 (completely tax-free if spent on qualified medical expenses) and saves you $2,769 in taxes this year alone.
Projected Balance
$480,064
2026 Contribution Limit
$8,750
Family coverage
Tax Saved This Year
$2,769
Income tax + FICA (payroll)
Your Numbers
Contributions above the IRS limit are automatically capped in this calculator. You must be enrolled in an HSA-eligible HDHP to contribute at all.
Projected HSA Balance
$8,750/year, 6% growth
Why an HSA Can Work as a Retirement Account
A Health Savings Account is designed to pay medical bills, but its tax treatment makes it one of the most efficient long-term savings vehicles available: money goes in tax-free, grows tax-free, and comes out tax-free for qualified medical expenses at any age, with no deadline to use it.
Future Value Formula
Balance after N years = each year's contribution, compounded forward at your return rate, summed across all N years
Worked example. Contributing the 2026 family HSA limit of $8,750/year, invested at a 6% annual return, grows to roughly $480,064 after 25 years. At a 24% marginal tax rate, contributing that $8,750 through payroll (Section 125) saves about $2,769 this year (31.65% combined savings: 24% income tax + 7.65% FICA) versus about $2,100 (24% only) if contributed outside of payroll.
What this doesn't cover. This calculator assumes every dollar contributed is invested rather than held as cash, and it doesn't model actual medical spending, HSA investment fees, or state tax treatment (a few states tax HSA contributions or growth differently than the federal government). Confirm your plan's HDHP eligibility and the current-year contribution limits at irs.gov (Publication 969), and talk to a fee-only financial planner about how an HSA fits into your broader retirement plan.
Frequently Asked Questions
?What makes an HSA "triple tax advantage"?
Contributions are tax-deductible (or pre-tax if made through payroll), the balance grows tax-free, and withdrawals for qualified medical expenses are tax-free at any age. No other account gets all three. Contribute via payroll and you also avoid FICA (Social Security and Medicare) tax on that portion, which a traditional 401(k) contribution does not avoid.
?Do I have to spend HSA money on medical costs right away?
No. Unlike an FSA, HSA funds never expire and there's no "use it or lose it" rule. Many people treat their HSA as a long-term investment account: paying smaller medical bills out of pocket, letting the HSA balance invest and grow, and saving receipts to reimburse themselves tax-free years or decades later.
?What happens to unused HSA money after age 65?
After 65, you can withdraw HSA funds for any purpose without the 20% penalty that applies before 65. Non-medical withdrawals are simply taxed as ordinary income, similar to a traditional IRA. Withdrawals for qualified medical expenses remain completely tax-free at any age, including after 65.
?Who is eligible to contribute to an HSA?
You must be enrolled in an HSA-eligible high-deductible health plan (HDHP) and have no other disqualifying health coverage (including being enrolled in Medicare). Check your specific plan's HDHP status and your eligibility at irs.gov or with your HR department before contributing.
?Why does contributing through payroll matter for taxes?
Contributions made through a payroll deduction (a Section 125 cafeteria plan) are exempt from both income tax and FICA payroll tax (7.65% combined Social Security and Medicare, on wages under the Social Security wage base). Contributions you make directly to your HSA outside of payroll are income-tax deductible, but they don't get the FICA exemption.
About this calculator. Results are estimates for education and planning, based on the inputs you enter and the published formula described above. Everything runs in your browser; nothing you type is sent to us or stored. It is not financial, tax, legal or medical advice. Read the disclaimer and our methodology.
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