HSA vs. FSA: Which Account Works for Your Situation

The core difference: how long your money lasts and who owns it

An HSA (Health Savings Account) is yours to keep forever. Money you put in stays in the account year after year, and you can use it whenever you need it — even after you retire or change jobs. An FSA (Flexible Spending Account) is tied to your job and your employer's plan year. Money you set aside for one year is gone if you don't spend it by the deadline, usually March 15 of the following year.

That single difference shapes almost everything else about how these accounts work. Because an HSA is yours permanently, it has fewer restrictions on what you can buy. Because an FSA is temporary and employer-run, it has stricter rules but also a faster tax break.

Both accounts let you set aside pre-tax money for medical costs — meaning the money comes out of your paycheck before taxes are calculated, so you pay less to the IRS. But the way that works, and what you can actually do with the money, is different enough that one will usually make more sense for your situation than the other.

Key Takeaways

• An HSA is a permanent account that rolls over year to year and belongs to you even if you leave your job, while an FSA is employer-based and you lose unspent money at the end of each plan year.
• You can only open an HSA if your health insurance is a high-deductible plan (usually $1,500 or more for individual coverage), but there is no insurance requirement for an FSA.
• An HSA lets you invest the money like a retirement account and use it for non-medical expenses after age 65, while an FSA money must be spent on medical costs or forfeited.
• An FSA gives you the money upfront at the start of the year, so you can use it immediately even if you have not finished paying in through payroll deductions.
• Most people with access to an HSA should use it instead of an FSA because the money does not disappear and you can build a long-term medical fund.

Who can open each account

To open an HSA, you must be enrolled in a high-deductible health plan (HDHP). Your employer's benefits materials will tell you which plans may have access to. For 2024, a high-deductible plan for individual coverage has a deductible of at least $1,500; for family coverage, at least $3,000. You cannot have other health insurance at the same time — no spouse's plan, no Medicare, no Medicaid — though there are narrow exceptions for specific types of coverage like dental-only or vision-only plans.

An FSA has no insurance requirement. Your employer simply has to offer one as part of their benefits package. You can be on any health plan — high-deductible, low-deductible, or no plan at all — and still open an FSA. However, not all employers offer FSAs, and some offer them only to certain groups of employees.

If your employer offers both, you can use an FSA for dependent care costs (childcare or adult day care) while also using an HSA for medical costs. You cannot use both for the same medical expense.

How much you can set aside each year

For an HSA, the contribution limit changes annually. In 2024, you can set aside up to $4,150 for individual coverage or $8,300 for family coverage. If you are 55 or older, you can add an extra $1,000. Your employer may contribute to your HSA as well — that money counts toward your limit but does not come out of your pocket.

For an FSA, the limit is lower and has been fixed for several years. In 2024, most employers allow you to set aside up to $3,200 per year for medical costs. Some employers set a lower limit. Dependent care FSAs have a separate limit of $5,000 per year (or $2,500 if you are married and file taxes separately).

Both accounts let you change your contribution only during your employer's open enrollment period, which is usually once a year in the fall. If you have a major life change — marriage, birth of a child, loss of other insurance — you may be able to change mid-year, but you have to notify your employer within 30 to 60 days of the event.

What you can spend the money on

Both accounts cover the same basic medical costs: doctor visits, prescriptions, dental work, vision care, mental health treatment, and medical equipment like crutches or blood pressure monitors. Both also cover some costs that surprise people, like over-the-counter pain relievers, sunscreen, and certain vitamins if a doctor prescribes them.

The difference emerges with less common expenses. An HSA is more flexible. You can use it for acupuncture, chiropractic care, fertility treatment, hearing aids, and many other services that fall outside traditional medicine. After you turn 65, you can use HSA money for anything at all — not just medical costs — without penalty, though you will owe income tax on non-medical withdrawals.

An FSA is stricter. Your employer's plan document spells out exactly what counts, and it is usually limited to services a doctor would prescribe or a hospital would bill for. Cosmetic procedures, gym memberships, and most over-the-counter items do not may have access to, even if they help your health.

What happens to money you don't spend

This is the biggest practical difference. HSA money rolls over automatically. If you set aside $2,000 and spend only $800, the remaining $1,200 stays in your account and earns interest or investment returns. You can let it grow for decades and use it whenever you need it.

FSA money follows a "use it or lose it" rule. If you do not spend what you set aside by the end of your plan year (usually December 31) plus a grace period (usually through March 15), the unspent money goes back to your employer. You cannot get it back. This is why many people set aside a conservative amount in an FSA — they would rather have less tax savings than risk losing money.

Some employers offer a small grace period or a carryover option that lets you roll $570 (in 2024) into the next year, but this is optional and not all employers use it. Check your employer's plan documents to see what applies to you.

How the tax savings work

Both accounts reduce your taxable income, which lowers what you owe the IRS. If you set aside $2,000 in either account and you are in the 22% tax bracket, you save roughly $440 in federal taxes. You also avoid payroll taxes (Social Security and Medicare), so the actual savings is closer to $300.

The difference is timing. With an FSA, your employer usually gives you access to the full year's amount on the first day of the plan year, even though you will pay it back gradually through payroll deductions. This means you can use the money immediately. With an HSA, the money is available only as you contribute it through payroll, so if you set aside $4,000 for the year, you have access to roughly $333 per month as it is deducted.

An HSA has an additional advantage: if you do not spend the money in a given year, it stays in the account earning interest or investment returns. Some HSAs let you invest the balance in mutual funds or stocks, similar to a retirement account. An FSA does not earn interest or grow — it is simply a spending account.

Which one makes sense for your situation

If you are enrolled in a high-deductible health plan, use the HSA. The money is yours permanently, you can invest it, and you have more flexibility on what you can buy. The only reason not to max out an HSA is if you do not have the cash to set aside.

If your employer does not offer an HSA or you are not on a high-deductible plan, an FSA can still save you money — but only if you are confident about how much you will spend. Set aside only what you are fairly sure you will use: regular prescriptions, ongoing therapy, planned dental work, or predictable medical costs. If you are unsure, set aside less rather than more. The tax savings on $1,500 you actually use is better than the tax savings on $3,200 you lose.

Some people have access to both. In that case, use the HSA for medical costs and the FSA for dependent care if you have childcare expenses. Do not try to use both for medical costs — the rules prohibit it, and your employer's payroll system will catch the error.

Frequently Asked Questions

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

Yes. Both accounts cover medical costs for you, your spouse, and any dependent children or relatives you claim on your taxes. The person receiving the care does not have to be on your health insurance plan.

What happens to my HSA if I leave my job?

Your HSA stays with you. It is your personal account, not your employer's. You keep the money, and you can continue to use it for medical costs for the rest of your life. If you move to a new job with a different HSA provider, you can roll the balance over to the new account, similar to rolling over a retirement account.

Can I use my FSA or HSA to pay for health insurance premiums?

You cannot use either account to pay premiums for your regular health insurance. You can use them to pay for premiums on supplemental coverage like dental-only or vision-only plans, and you can use an HSA to pay Medicare premiums after you turn 65.

What if I change jobs mid-year?

Your FSA usually ends when you leave your employer, and you lose any unspent balance. Some employers offer a continuation option (similar to COBRA for health insurance) that lets you keep spending from the FSA for a limited time, but this is rare. Your HSA moves with you and stays active regardless of employment changes.

Do I have to submit receipts to use my HSA or FSA?

Most of the time, no. You can usually just swipe a debit card linked to the account at a pharmacy or doctor's office. However, the account administrator may ask you to provide proof that an expense was medical if it is unclear — for example, if you buy something at a drugstore that could be medical or personal. Keep receipts for a few years just in case.