A Health Savings Account (HSA) is a tax-advantaged account you can use to pay for qualified medical expenses. It was created by Congress in 2003, and over 35 million Americans now have one. If you're enrolled in the right kind of health plan, an HSA is almost certainly the most tax-efficient account you can fund. Here's everything you need to know to get started.
The Basics
An HSA has four defining features:
- You own it. Unlike an FSA, the account is yours — it doesn't reset at year-end and it follows you when you change jobs.
- It has a triple tax advantage. Contributions are tax-deductible, growth is tax-free, and withdrawals for qualified medical expenses are tax-free. No other account combines all three.
- You must be in a qualifying health plan — a High-Deductible Health Plan (HDHP) — to contribute. You don't need to stay in an HDHP to spend from the account, only to fund it.
- The money can be invested. Most major HSA custodians let you put your balance into low-cost index funds once it crosses a small threshold.
Who Can Open One?
You're eligible to contribute to an HSA in any month where you:
- Are enrolled in a qualifying HDHP
- Have no other disqualifying coverage (general-purpose FSA, traditional health plan, Medicare, TRICARE, etc.)
- Are not claimed as a dependent on someone else's tax return
The HDHP requirement has specific dollar thresholds for the deductible and out-of-pocket maximum that the IRS updates annually — see the 2026 contribution limits and HDHP requirements for the current numbers.
The Triple Tax Advantage Explained
This is the magic of the HSA. Compare to other accounts:
| Account | Contribution | Growth | Withdrawal |
|---|---|---|---|
| Traditional 401(k)/IRA | Tax-free | Tax-free | Taxed |
| Roth 401(k)/IRA | Taxed | Tax-free | Tax-free |
| HSA | Tax-free | Tax-free | Tax-free* |
*For qualified medical expenses. Non-qualified withdrawals before 65 are taxed and penalized; after 65 they're just taxed as ordinary income.
For a full breakdown with real-dollar examples, see HSA Tax Benefits: 3 Ways to Save Money.
How Much Can You Contribute?
For 2026, the limits are $4,400 if you have self-only HDHP coverage and $8,750 for family coverage. People age 55 or older can contribute an additional $1,000 catch-up. Contributions can come from you, your employer, or both — but the combined total can't exceed the annual limit.
What Counts as a Qualified Medical Expense?
Far more than people realize. The IRS publishes the official list in Publication 502, but it includes everything from doctor visits and prescriptions to dental, vision, mental health therapy, OTC medications, period products, sunscreen, and even some travel for medical care. Browse our searchable directory of 890+ HSA-eligible items to check anything specific.
HSA vs. FSA — Don't Confuse Them
HSAs and Flexible Spending Accounts (FSAs) are often discussed together, but they're very different. The biggest practical differences: an HSA is yours forever and the money never expires; an FSA is owned by your employer and most of it disappears at year-end. Read our full HSA vs FSA comparison to figure out which makes sense for you (you can sometimes use both).
The Most Powerful Strategy
Here's where most beginners miss out. The default approach — funding the HSA, then immediately spending it on doctor visits — is fine, but it skips the best feature. Because there's no time limit on when you can reimburse yourself, you can pay current medical bills out of pocket, save the receipts, and let your HSA balance grow invested for decades. Years later, you withdraw funds tax-free against those old receipts.
This is called the shoebox strategy, and combined with treating your HSA as a stealth retirement account, it can dramatically outperform any other tax-advantaged account on a long horizon. Run your numbers in the HSA ROI calculator.
How to Open an HSA
- Confirm you're enrolled in a qualifying HDHP. Check your benefits summary or call HR.
- Pick a custodian. If your employer offers one, that's the easiest path for payroll deductions (which also save you 7.65% in FICA tax). You can also open your own — see our top HSA investment provider rankings.
- Set up contributions. Either through payroll, or by transferring from your bank account (deductible on your tax return).
- Invest the balance. Don't leave it in cash — pick a low-cost index fund.
- Set up a receipt system. See our guide to HSA receipt storage.
Common Beginner Questions
Can I have an HSA and a 401(k)? Yes. They're independent and you can max both.
What if I leave my employer? The HSA is yours. You can keep contributing if you stay in an HDHP, or just spend it down. You can also transfer it to a different custodian.
What if I never use the money? It rolls over forever. After age 65 the 20% penalty for non-medical withdrawals disappears, so it functions like a Traditional IRA for non-medical use.
What about my spouse and kids? You can use HSA funds for any tax dependent's qualified medical expenses, even if they're not on your HDHP.
The Bottom Line
If you're eligible and not contributing to an HSA, you're leaving real money on the table. Open one, fund it, invest the balance, and save your receipts. It's the closest thing to a free lunch in the U.S. tax code.