Short answer
A Health Savings Account (HSA) is the only US account with a triple tax advantage: money goes in before tax, grows tax-free while invested, and comes out tax-free for medical costs. You need a high-deductible health plan (HDHP) to open one. As of 2025 the individual limit was $4,300 (check the current year). Unlike an FSA it's not use-it-or-lose-it — unused money rolls over, stays yours, and after 65 you can withdraw it for anything.
The triple tax advantage
No other US account gives you all three of these at once:
- Pre-tax in — contributions lower your taxable income this year.
- Tax-free growth — invested money compounds with no tax.
- Tax-free out — withdrawals for qualified medical costs are never taxed.
A 401(k) gives you the first two; a regular brokerage gives you none. The HSA gives you all three, which is why it's so valuable once you know it exists.
You need an HDHP to open one
You can only contribute to an HSA if you're enrolled in a high-deductible health plan (HDHP), which is usually one of the options at benefits enrollment. If you're young and healthy, the HDHP + HSA pairing is often a strong default — but weigh the higher deductible against your expected medical needs.
HSA vs FSA
| HSA | FSA | |
|---|---|---|
| Requires an HDHP | Yes | No |
| Unused money rolls over | Yes — always | Mostly use-it-or-lose-it |
| Stays yours if you leave | Yes | No |
| Can be invested | Yes | No |
Invest it — don't just spend it
Most HSAs let you invest the balance once it passes a threshold. Because growth and qualified withdrawals are tax-free, many people pay current medical costs out of pocket and let the HSA compound for decades — effectively a stealth retirement account.
Contribution limits
As of 2025, the limit was $4,300 for an individual and higher for a family (limits usually rise each year — check the current IRS figure). Any contribution your employer makes counts toward that limit.
After 65 it becomes flexible
Once you turn 65, you can withdraw HSA money for anything — it's simply taxed as income, with no penalty, like a traditional retirement account. Use it for medical costs and it stays completely tax-free.
Frequently asked
What is the triple tax advantage of an HSA?
Contributions go in before tax, the money grows tax-free while invested, and withdrawals for qualified medical expenses come out tax-free. No other US account offers all three.
Do I lose HSA money at the end of the year?
No. Unlike an FSA, an HSA is not use-it-or-lose-it. Unused funds roll over every year and remain yours.
Can I keep my HSA if I leave my job or the US?
Yes. An HSA is yours and is fully portable — it stays with you if you change employers or leave the country.
What's the difference between an HSA and an FSA?
An HSA requires a high-deductible health plan, rolls over, is portable, and can be invested. An FSA works with any plan but is mostly use-it-or-lose-it and not portable.