HSA vs. FSA: Which Health Savings Account Is Right for You?

What Is an HSA?

A Health Savings Account (HSA) is a tax-advantaged account you open alongside a qualifying High-Deductible Health Plan (HDHP). Money goes in pre-tax, grows tax-free, and comes out tax-free when you use it for qualified medical expenses. That triple tax break is the best deal in the U.S. tax code for health spending.

You own the HSA — not your employer. It moves with you if you change jobs, change plans, or retire. Unused money rolls over every single year with no limit. After age 65, you can even withdraw funds for non-medical purposes and pay only ordinary income tax, just like a traditional IRA.

To open or contribute to an HSA in 2025, your health plan must qualify as an HDHP: a deductible of at least $1,650 for self-only coverage or $3,300 for family coverage, and out-of-pocket maximums no higher than $8,300 (self-only) or $16,600 (family), per IRS rules.

What Is an FSA?

A Flexible Spending Account (FSA) is an employer-sponsored account that lets you set aside pre-tax dollars for medical expenses. Unlike an HSA, you can open a health care FSA regardless of what type of health plan you have. You do not need an HDHP.

The catch: FSAs are subject to the IRS use-it-or-lose-it rule. You must spend your contributions within the plan year or forfeit what remains. Employers can offer a grace period of up to 2.5 months or let you roll over up to $660 in 2025 — but they cannot offer both, and not every employer offers either option.

One important FSA feature: your full annual election is available on day one of the plan year, even though you fund it through paycheck deductions over the year. That front-loaded access can help if you have a major expense in January.

The Three Big Differences That Matter Most

The HSA wins on longevity. Every unused dollar stays in your account, grows with investment earnings, and can fund retirement health costs or just sit there for decades. The FSA is designed to be spent by December 31.

The FSA wins on eligibility. You do not need a specific plan type. If your employer offers an FSA, you can use it with a standard PPO or HMO. The HSA requires you to first be enrolled in an HDHP — and you cannot contribute to an HSA if you have other disqualifying coverage, including Medicare.

The HSA wins on portability. Your FSA balance generally disappears if you leave your job mid-year. Your HSA balance goes with you everywhere, forever.

Sources: IRS Rev. Proc. 2024-25 (HSA limits); IRS Rev. Proc. 2024-40 (FSA limit); IRS Publication 969.

Which One Should You Choose?

If your employer offers an HDHP alongside an HSA, and you are generally healthy, the HSA is almost always the better long-term bet. You get a lower premium on the HDHP, a triple tax benefit on the HSA, and every dollar you do not spend this year becomes a dollar saved for future medical costs — or retirement.

If you have a chronic condition, see specialists regularly, or take expensive prescriptions, a lower-deductible plan with an FSA might cost you less overall, even without the HSA's tax advantages. Run the math on your expected annual spending before deciding.

Some people can run both: if you have an HSA-eligible HDHP, your employer may also offer a Limited-Purpose FSA (LPFSA) restricted to dental and vision. You can contribute to both simultaneously. That is as close to a no-brainer as health benefits get.

Qualified Medical Expenses for Both Accounts

Both HSAs and FSAs cover the same broad list of qualified medical expenses as defined by IRS Publication 502: doctor visits, prescriptions, dental and vision care, mental health services, acupuncture, medical equipment, and hundreds of other items. The CARES Act of 2020 permanently added over-the-counter medications and menstrual care products to the list.

What they do not cover: health insurance premiums (with limited HSA exceptions for COBRA, long-term care insurance, and Medicare premiums after 65), cosmetic procedures, and general wellness items like gym memberships unless prescribed.

Keep your receipts. The IRS can audit HSA or FSA distributions years later. A simple folder — physical or digital — for every expense is enough protection.