How FSA and HSA Accounts Work: The Core Difference

FSA and HSA are tax-advantaged accounts that let you set aside pre-tax money for medical expenses, but they work under different rules and belong to different people

A Flexible Spending Account (FSA) is an employer-sponsored account where you contribute money before taxes are taken out of your paycheck. That money sits in the account and you use it to pay for may be able to access medical, dental, and vision expenses. Your employer may also contribute to it.

A Health Savings Account (HSA) is a personal savings account tied to a high-deductible health insurance plan. You contribute pre-tax money, it grows over time, and you can use it for medical expenses now or save it for later. Unlike an FSA, an HSA stays with you even if you change jobs.

Both accounts reduce the amount of income tax you owe because the money going in is not counted as taxable income. The practical difference comes down to who owns the account, what happens to unused money, and what insurance plan you need to have one.

Key Takeaways

FSA money comes from your paycheck through your employer and must be spent within the plan year or you lose it, though some plans allow a small carryover or grace period.
HSA money is yours to keep and grows year to year, and you can use it for medical expenses at any point in your life, even after retirement.
You can only open an HSA if you are enrolled in a high-deductible health plan; FSA is available to anyone whose employer offers it.
Both accounts cover the same types of expenses: copays, deductibles, prescriptions, dental work, vision care, and many other medical costs.
If you have access to both, you can contribute to an FSA and an HSA in the same year, but the rules about what you can spend from each are strict.

Who can open an FSA versus an HSA

An FSA is offered by your employer as part of the benefits package. If your company offers one, you can usually enroll during open enrollment or within 30 days of hire. You do not need any particular type of health insurance to have an FSA—it works alongside whatever plan your employer provides.

An HSA requires that you are enrolled in a high-deductible health plan (HDHP). The IRS sets the minimum deductible each year; for 2024, a self-only plan must have a deductible of at least $1,600 and a family plan at least $3,200. If your employer offers an HDHP, you can open an HSA. You can also open one on your own if you buy an HDHP through the individual market or a spouse's employer offers one.

You cannot have an FSA and an HSA at the same time if the FSA is a general-purpose account. However, some employers offer a limited-purpose FSA that covers only dental and vision expenses, which you can pair with an HSA.

How money flows in and out of each account

With an FSA, you decide at the start of the plan year how much to contribute—typically between $100 and $3,200 per year, though your employer sets the exact limit. That amount is divided across your paychecks and deducted before income tax is calculated. When you have a medical expense, you submit a receipt or claim form to the FSA administrator and they reimburse you from the account.

With an HSA, you can contribute money in several ways: through payroll deduction (like an FSA), by depositing money directly into the account, or by transferring funds from another HSA. The annual contribution limit is set by the IRS and varies by whether you have self-only or family coverage. For 2024, the limit is $4,150 for self-only coverage and $8,300 for family coverage. You can contribute until the tax filing deadline the following year.

HSA money can be withdrawn by writing a check, using a debit card linked to the account, or requesting a reimbursement. Many HSA providers also let the account earn interest or invest the money, so it can grow over time.

What happens to money you do not spend

FSA money operates on a "use it or lose it" rule. Any balance remaining at the end of the plan year is forfeited and goes back to your employer. However, many employers now offer either a carryover (usually up to $610 in 2024) or a grace period (usually 2.5 months into the next year) to spend remaining funds. Check your plan documents to see which option your employer uses.

HSA money is yours to keep indefinitely. If you do not spend it in a given year, it rolls over to the next year and the year after that. The account can accumulate over decades. This makes an HSA function partly as a retirement savings tool—you can use HSA funds for medical expenses in retirement, and after age 65 you can withdraw money for any reason (though non-medical withdrawals are taxed as income).

may be able to access expenses you can pay for with either account

Both FSA and HSA cover a broad range of medical, dental, and vision costs. Copays, coinsurance, and deductibles are covered. Prescription medications, insulin, and over-the-counter drugs (with a prescription) are covered. Dental work including cleanings, fillings, root canals, and orthodontia are covered. Vision expenses including eye exams, glasses, and contact lenses are covered.

Other covered expenses include mental health counseling, physical therapy, chiropractic care, hearing aids, medical equipment like crutches or wheelchairs, and certain medical supplies. The IRS publishes a detailed list, and most FSA and HSA administrators provide a searchable database of may be able to access items on their websites.

Expenses that are not covered include cosmetic procedures, gym memberships, vitamins (unless prescribed for a specific condition), and over-the-counter items without a prescription. If you are unsure whether an expense qualifies, ask your account administrator before you pay—using account funds for ineligible expenses can trigger taxes and penalties.

Tax advantages and how they differ

Both accounts save you money on taxes because contributions are deducted before federal income tax, Social Security tax, and Medicare tax are calculated. If you contribute $2,000 to an FSA and you are in the 22% tax bracket, you save roughly $440 in federal taxes alone, plus additional savings on payroll taxes.

The HSA has an additional advantage: money withdrawn for medical expenses is not taxed at all, and the account can earn interest or investment returns tax-free. This makes it a more powerful long-term savings tool. An FSA saves you taxes on the contribution, but you must spend the money within the plan year or lose it.

If you have both an FSA and an HSA, you cannot use both to pay for the same expense. For example, if you have a $500 dental bill, you can pay it from your FSA or your HSA, but not split it between them. The IRS treats this as a form of double-dipping and will tax the second payment.

Choosing between FSA and HSA, or using both

If your employer offers only an FSA, the choice is simple: an FSA is better than nothing if you have predictable medical expenses. Contribute an amount you are confident you will spend within the year, because unused money is lost.

If you have access to an HSA through a high-deductible plan, an HSA is usually the stronger choice for long-term savings because money rolls over and grows. However, a high-deductible plan means you pay more out of pocket before insurance kicks in, so you need enough cash on hand to cover that deductible.

If your employer offers both a limited-purpose FSA (covering only dental and vision) and an HSA, you can use both. Contribute to the FSA for predictable dental and vision costs, and use the HSA for everything else and for long-term savings.

Frequently Asked Questions

Can I use my FSA or HSA to pay for my spouse's or child's medical expenses?

Yes. Both accounts can pay for the medical expenses of your spouse and any dependent you claim on your tax return, even if they are not covered under your health plan. You will need receipts showing the expense and proof of the relationship.

What happens to my FSA if I leave my job?

You lose access to the FSA. Any remaining balance is forfeited. However, you may be able to continue coverage under COBRA for a limited time, which would let you use the remaining balance. Check with your employer's benefits office about COBRA may be able to access.

Can I roll over my HSA balance if I change jobs?

Yes. An HSA is your personal account and moves with you. You can transfer the balance to a new HSA at a different provider, or simply keep the old account open and continue using it. You do not have to close it when you change employers.

What if I withdraw money from my HSA for a non-medical expense before age 65?

You will owe income tax on the withdrawal plus a 20% penalty. After age 65, you can withdraw money for any reason and owe only income tax, not the penalty. Keep receipts for all medical expenses in case the IRS asks.

Do I need to submit receipts every time I use my FSA or HSA debit card?

It depends on your provider and the type of expense. Some providers require receipts for all purchases; others only for certain categories. Many now use real-time may be able to access checking at pharmacies and medical offices. Check your account provider's rules and keep receipts for at least three years.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.