An FSA is a tax-advantaged account where you set aside pre-tax money to pay for medical expenses your insurance doesn't cover

A Flexible Spending Account (FSA) lets you put money into an account before taxes are taken out of your paycheck, then use that money to pay for out-of-pocket medical costs. The tax savings come from the fact that the money you contribute never gets taxed as income — you're setting it aside before your employer calculates what you owe in federal income tax and payroll taxes.

The catch is that FSAs are "use it or lose it." Money you don't spend by the end of the plan year (usually December 31) goes back to your employer. Some plans allow a small carryover or a grace period, but most do not. This is why FSAs work best if you can predict your medical spending fairly accurately.

FSAs are offered through your employer. You enroll during open enrollment, usually in the fall, and the account runs on your employer's plan year. You cannot open an FSA on your own — it has to come through a workplace benefits package.

Key Takeaways

  • FSA contributions come out of your paycheck before taxes, which reduces your taxable income and the amount you owe in federal and payroll taxes.
  • You decide how much to contribute each year during open enrollment, and that money sits in an account you control to pay for may be able to access medical expenses.
  • The "use it or lose it" rule means unspent money at the end of the plan year typically goes back to your employer, so you need to estimate your spending carefully.
  • FSAs cover many out-of-pocket costs that insurance doesn't — copays, deductibles, prescriptions, dental work, vision care, and some medical equipment — but not health insurance premiums or cosmetic procedures.
  • You access FSA money through a debit card, reimbursement forms, or direct payment to providers, depending on how your employer's plan is set up.

What you can and cannot spend FSA money on

FSA funds cover may have access to medical expenses — the IRS publishes a list, and it is longer than most people expect. Copays, coinsurance, deductibles, prescription medications, dental work, vision care (including glasses and contacts), hearing aids, and certain medical equipment all count. You can also use FSA money for over-the-counter medications if you have a prescription or a doctor's note, and for things like crutches, bandages, and blood pressure monitors.

What does not count: health insurance premiums (with one exception: COBRA premiums), cosmetic procedures, gym memberships, vitamins without a medical reason, and most wellness products. Sunscreen, for example, is not covered unless a dermatologist prescribes it for a specific skin condition.

The IRS updates the list of may be able to access expenses periodically. If you are unsure whether something qualifies, your plan administrator can tell you — they have access to the current rules and can give you a yes or no before you spend the money.

How much you can contribute and how the money works

The IRS sets an annual contribution limit for FSAs. For 2024, the limit is $3,200 per person per year. Your employer may set a lower limit, but not a higher one. You decide how much to contribute during open enrollment, and that amount is divided across your paychecks for the year.

Once money is in your FSA, it belongs to you — your employer cannot take it back or use it for anything else. If you leave your job, you can usually continue to spend down your FSA balance for a limited time (typically 60 to 90 days), but you cannot add new contributions. If you have money left when that window closes, it is forfeited.

Some employers offer a grace period (usually 2.5 months into the next plan year) or a limited carryover (up to $610 in 2024) so you do not lose unspent money. Check your plan documents to see if yours does.

How to access your FSA money

Most FSA plans issue a debit card that you can use at pharmacies, doctor's offices, and medical suppliers. The card is tied to your account balance, and you can only spend what you have contributed so far that year. Some plans require you to submit receipts after you use the card, so keep documentation.

If your plan does not have a debit card, you pay out of pocket and then submit a reimbursement form with receipts to your plan administrator. They review the claim and send you a check or direct deposit. This process usually takes one to two weeks.

A few plans let you pay providers directly — your employer or plan administrator handles the payment on your behalf. Ask your benefits team which method your plan uses.

FSA versus HSA: when each one makes sense

An FSA and an HSA (Health Savings Account) are both tax-advantaged, but they work differently and have different rules. An FSA is available to anyone with a health plan through their employer. An HSA is only available if you have a high-deductible health plan (HDHP), and it rolls over year to year instead of using the "use it or lose it" rule.

If your employer offers both, the choice depends on your situation. An FSA makes sense if you have predictable medical expenses and want to save on taxes without worrying about long-term savings. An HSA makes sense if you have a high deductible, want to build up savings over time, and can afford to pay medical costs out of pocket now. Some people with an HDHP use both — they max out their HSA first (because the money rolls over), then use an FSA for additional tax savings on predictable costs.

What happens to unused FSA money

At the end of your plan year, any money you did not spend is forfeited. Your employer keeps it — this is why the "use it or lose it" rule exists. It is a real constraint, and it means you need to be honest about what you will actually spend.

The best strategy is to estimate conservatively. If you usually spend $1,500 on medical costs in a year, contribute $1,500 or slightly less, not $3,200. If you are unsure, start low and increase your contribution next year once you have a sense of your actual spending.

Some plans offer a grace period or carryover, which gives you a small buffer. Check your plan documents or ask your benefits team whether yours does. If it does, you have a bit more flexibility — but do not count on it unless you know for certain.

How FSA contributions affect your taxes

When you contribute to an FSA, that money is deducted from your gross income before federal income tax and payroll taxes (Social Security and Medicare) are calculated. This means you pay less in taxes overall.

The tax savings depend on your tax bracket. If you are in the 22% federal tax bracket and contribute $2,000 to an FSA, you save roughly $440 in federal taxes alone. Add state income tax and payroll taxes, and the total savings can be 25% to 40% of what you contribute. That is real money, and it is one of the main reasons FSAs exist.

You do not pay taxes on the money you spend from your FSA, and you cannot claim those same expenses as a deduction on your tax return — you have already gotten the tax benefit by contributing pre-tax money.

Frequently Asked Questions

Can I change my FSA contribution during the year?

No, not usually. FSA contributions are locked in during open enrollment and cannot be changed unless you have a may have access to life event — marriage, divorce, birth of a child, loss of other health coverage, or a significant change in your health plan. Your employer's benefits team can tell you what counts as may have access to.

What if I do not use all my FSA money by the end of the year?

It is forfeited and goes back to your employer. Some plans offer a grace period (usually 2.5 months into the next year) or allow you to carry over up to $610, but most do not. Check your plan documents to see if yours does.

Can I use my FSA debit card at any store?

No. FSA debit cards only work at pharmacies, doctor's offices, hospitals, dental offices, vision centers, and other medical providers. They will not work at grocery stores or general retailers, even if you are buying something medical like a thermometer.

What happens to my FSA if I leave my job?

You can usually continue to spend down your FSA balance for 60 to 90 days after you leave, but you cannot add new contributions. After that window closes, any unspent money is forfeited. Some employers extend this period, so ask your benefits team.

Is an FSA worth it if I do not have many medical expenses?

Only if you have some predictable costs — copays, prescriptions, dental work, or vision care. If you rarely see a doctor and do not take regular medications, the tax savings may not be worth the risk of losing unspent money. Start with a small contribution if you are unsure.