A health savings account might be the most powerful tax-advantaged tool most Americans never fully use. If you’ve asked yourself “what is an HSA,” you’re not alone — despite being available since 2004, HSAs remain widely misunderstood. At their core, they combine triple tax advantages with long-term savings potential, making them uniquely valuable for managing healthcare costs today and building a medical nest egg for retirement. This guide breaks down how HSAs work, who qualifies, and how to make the most of yours. For more on navigating the complexities of the US healthcare system, see our healthcare policy guide.
How a Health Savings Account Works
An HSA is a tax-advantaged savings account designed specifically for medical expenses. You contribute pre-tax dollars, the money grows tax-free through interest or investments, and withdrawals for qualified medical expenses are also tax-free. This “triple tax advantage” is unique among all savings vehicles in the US tax code — even 401(k)s and IRAs can’t match it.
To open and contribute to an HSA, you must be enrolled in a high-deductible health plan (HDHP). For 2025, the IRS defines an HDHP as a plan with a minimum deductible of $1,650 for individual coverage or $3,300 for family coverage, with maximum out-of-pocket limits of $8,300 for individuals and $16,600 for families. You cannot be enrolled in Medicare, claimed as a dependent on someone else’s tax return, or have other non-HDHP health coverage (with limited exceptions like dental, vision, and certain supplemental plans).
Unlike a flexible spending account, HSA funds roll over indefinitely — there’s no “use it or lose it” deadline. The account belongs to you, not your employer, and remains yours even if you change jobs, switch health plans, or retire. This portability is one of the HSA’s most underappreciated features.
HSA Contribution Limits and Tax Benefits
For 2025, the IRS allows maximum contributions of $4,300 for individual coverage and $8,550 for family coverage. If you’re 55 or older, you can contribute an additional $1,000 catch-up contribution. Contributions can come from you, your employer, or a combination — but the total from all sources cannot exceed the annual limit.
The tax savings are substantial. Contributions made through payroll deduction are excluded from federal income tax, Social Security tax (FICA), and state income tax in most states (California and New Jersey are notable exceptions). If you contribute outside of payroll, you can deduct the amount on your federal tax return. According to the IRS (Publication 969), these deductions are available even if you don’t itemize — they’re “above the line” deductions that reduce your adjusted gross income.
Investment growth within the HSA — whether from interest, dividends, or capital gains — is completely tax-free. And when you withdraw funds for qualified medical expenses, you pay zero tax on those withdrawals. For someone in the 22% federal tax bracket, every $1,000 contributed to an HSA effectively costs only about $700 after tax savings. Over a career, this advantage compounds dramatically.
What Can You Spend HSA Money On?
The list of qualified medical expenses is broader than many people expect. It includes doctor visits, hospital stays, prescription medications, dental care (cleanings, fillings, crowns, orthodontics), vision care (exams, glasses, contact lenses, LASIK), mental health services, chiropractic care, and physical therapy. Over-the-counter medications, menstrual products, sunscreen, and first aid supplies have been eligible since the CARES Act of 2020.
You can also use HSA funds for health insurance premiums in limited circumstances — specifically, COBRA continuation coverage, health coverage while receiving unemployment benefits, and Medicare premiums (Parts A, B, D, and Medicare Advantage) once you turn 65. Long-term care insurance premiums are partially deductible through HSAs based on age-based limits. A full list of qualified expenses is available in IRS Publication 502.
Non-qualified withdrawals before age 65 are subject to income tax plus a 20% penalty — a steep deterrent. After 65, non-qualified withdrawals are taxed as ordinary income (like a traditional IRA) but the penalty disappears. This makes the HSA a flexible retirement savings tool even beyond medical expenses, though the tax advantage is greatest when used for healthcare.
HSA as a Retirement Strategy
Financial planners increasingly view HSAs as powerful retirement vehicles. Fidelity estimates that the average 65-year-old couple retiring today will need approximately $315,000 for healthcare expenses in retirement — and that figure doesn’t include long-term care. An HSA funded consistently throughout a career can make a significant dent in that number.
The optimal strategy, for those who can afford it, is to maximize HSA contributions each year while paying current medical expenses out of pocket. This allows the HSA balance to grow and compound tax-free for decades. Many HSA providers offer investment options — mutual funds, index funds, and target-date funds — similar to a 401(k). Keeping receipts for medical expenses you pay out of pocket allows you to reimburse yourself from the HSA at any point in the future, even years later, as long as the expense occurred after the HSA was established.
After age 65, the HSA effectively functions like a traditional IRA for non-medical withdrawals (taxed as income but no penalty), while still providing tax-free withdrawals for medical expenses. Combined with the upfront tax deduction, this makes the HSA arguably more tax-efficient than a Roth IRA for people who will have healthcare expenses in retirement — which is virtually everyone.
How to Open and Manage an HSA
Many employers that offer HDHPs will facilitate HSA enrollment and may even make employer contributions. If your employer doesn’t offer an HSA, or if you’re self-employed, you can open one independently through banks, credit unions, or specialized HSA administrators like Fidelity, Lively, or HSA Bank. When choosing a provider, compare monthly fees, investment options, interest rates, and user experience.
Look for an HSA provider with no monthly maintenance fees (or fees that are waived above a certain balance), low-cost investment options, and a user-friendly app for tracking expenses and submitting claims. The Centers for Medicare and Medicaid Services (CMS) provides additional guidance on HDHP qualification requirements that determine your HSA eligibility.
Keep meticulous records of medical expenses, even if you don’t reimburse yourself immediately. Save receipts digitally — many HSA apps allow you to photograph and store receipts within the platform. The IRS can audit HSA withdrawals, so documentation of qualified expenses is essential. If you’re curious about how HSAs compare to another popular option, read our guide on flexible spending accounts (FSAs) or our detailed HSA vs FSA comparison.
Common HSA Mistakes to Avoid
The biggest mistake is not contributing at all. Only about 13% of HSA holders maximize their annual contributions, according to the Employee Benefit Research Institute. The second most common error is treating the HSA purely as a spending account rather than a long-term savings vehicle. While it’s perfectly fine to use HSA funds for current expenses, those who can afford to invest and let the balance grow will benefit most from the compounding tax advantages.
Other pitfalls include using HSA funds for non-qualified expenses before 65 (triggering the 20% penalty), forgetting to update beneficiary designations, not investing the balance above what you need for near-term expenses, and failing to keep receipts for reimbursement. Also, remember that you cannot contribute to an HSA once you enroll in Medicare — even Medicare Part A — so plan your final contribution year carefully. Understanding your health insurance deductible helps you estimate how much to keep liquid in your HSA for near-term medical costs.
Frequently Asked Questions
Can I use my HSA for my spouse or dependents?
Yes. You can use HSA funds for qualified medical expenses incurred by your spouse and tax dependents, even if they aren’t covered by your HDHP. However, your spouse cannot also contribute to their own HSA unless they have their own HDHP coverage. Family contribution limits apply when you have family HDHP coverage.
What happens to my HSA if I leave my job?
The HSA is yours — it stays with you regardless of employment changes. You can continue to use the existing balance for qualified medical expenses. However, you can only make new contributions if you remain enrolled in an HDHP. If your new employer offers a different HDHP, you can continue contributing. If not, the balance remains available for spending but you can’t add more.
Can I have both an HSA and an FSA?
Generally, no — having a general-purpose FSA disqualifies you from HSA contributions. However, you can pair an HSA with a “limited-purpose FSA” (restricted to dental and vision expenses) or a “post-deductible FSA” (which only kicks in after you meet your HDHP deductible). Check with your employer’s benefits administrator for available combinations.
Do HSA funds expire?
No. Unlike FSAs, HSA funds never expire. There is no annual forfeiture and no deadline to spend the balance. Money contributed to your HSA remains in the account indefinitely, continuing to grow tax-free until you withdraw it. This is one of the most significant advantages of HSAs over FSAs.
The Bottom Line
An HSA is one of the few financial tools that offers tax deductions on the way in, tax-free growth, and tax-free withdrawals — all in one account. If you’re eligible through a high-deductible health plan, contributing to an HSA should be a priority, whether you use the funds for current medical expenses or invest them for the future. The combination of immediate tax savings and long-term compounding makes it a uniquely powerful tool for healthcare costs at every stage of life. Start by checking whether your health plan qualifies, then open an account and begin contributing — even small amounts add up significantly over time.