An FSA is a tax-advantaged savings account your employer offers to set aside money for medical expenses

A Flexible Spending Account (FSA) is an account where you contribute pre-tax money from your paycheck to pay for may have access to medical and dependent care costs. Your employer deducts the money before income tax is calculated, which means you pay less in taxes overall. The money sits in the account and you withdraw it as you incur may be able to access expenses throughout the year.

FSAs are offered through your employer's benefits plan — you cannot open one on your own. Not all employers offer them, and the rules vary slightly depending on your employer's plan design. The account is "use it or lose it," meaning money you don't spend by the end of the plan year generally cannot be carried forward, though some employers allow a small carryover or grace period.

Key Takeaways

  • FSA contributions come from your paycheck before taxes are taken out, reducing your taxable income and the taxes you owe.
  • You can use FSA money to pay for copays, deductibles, prescriptions, dental work, vision care, and other may have access to medical expenses.
  • Money you don't spend by the end of the plan year is forfeited, so you need to estimate carefully how much to contribute.
  • You enroll in an FSA during your employer's open enrollment period, usually once per year, and contributions are locked in for the full year.
  • FSAs are separate from health insurance; you can have both an FSA and a high-deductible health plan, or an FSA and a traditional health plan.

How money flows in and out of an FSA

You decide how much to contribute each year during your employer's open enrollment period — typically in the fall for coverage starting January 1. The amount you choose is divided by the number of pay periods remaining in the year, and that amount is deducted from each paycheck before taxes. For example, if you contribute $2,400 for the year and are paid biweekly, roughly $92 comes out of each check.

When you have a medical expense, you pay for it out of pocket and then request reimbursement from your FSA administrator (the company your employer hired to manage the account). You submit a claim with a receipt or explanation of benefits, and the administrator sends you the money. Some FSAs issue a debit card that you can use directly at pharmacies or medical offices, though you may still need to submit receipts afterward to prove the expense was may be able to access.

The money you contribute is yours to use — your employer does not own it. However, if you leave your job or change to a different health plan outside of open enrollment, you typically lose access to any money remaining in the account.

What expenses an FSA covers

FSAs cover a broad range of medical and dependent care costs. Medical expenses include copays, coinsurance, deductibles, prescription medications, glasses and contact lenses, dental work, hearing aids, and mental health counseling. You can also use FSA money for over-the-counter medications (with a prescription from your doctor), medical equipment like crutches or blood pressure monitors, and transportation to medical appointments.

Dependent care FSAs are separate accounts some employers offer for childcare or adult daycare expenses. Money in a dependent care FSA cannot be used for medical costs, and vice versa.

Expenses that do not may have access to include cosmetic procedures, gym memberships, vitamins (unless prescribed by a doctor for a specific condition), and most over-the-counter items unless your doctor writes a prescription. Your FSA administrator can tell you whether a specific expense qualifies before you submit a claim.

The tax advantage and the trade-off

The main benefit of an FSA is the tax savings. Because contributions are deducted before income tax, Social Security tax, and Medicare tax are calculated, you reduce the amount of taxes you owe. If you contribute $2,400 to an FSA and are in the 22% federal tax bracket, you save roughly $528 in federal taxes alone, plus state and payroll taxes depending on where you live.

The trade-off is the "use it or lose it" rule. Money you do not spend by December 31 (or by the end of your employer's plan year) is forfeited — you cannot roll it over to the next year or withdraw it. Some employers allow a grace period of up to 2.5 months into the next year, or a carryover of up to $610 (the amount changes yearly), but most do not. This means you need to estimate carefully how much medical spending you expect in the coming year.

If you are unsure how much to contribute, a conservative approach is to set aside only the medical expenses you know are coming — copays for regular prescriptions, annual dental cleanings, or scheduled procedures. This reduces the risk of losing money while still capturing some tax savings.

FSA vs. HSA: when you might have both

An HSA (Health Savings Account) is different from an FSA. HSAs are available only if you have a high-deductible health plan, and money rolls over year to year — you do not lose it. HSAs also have a higher contribution limit and can be invested. However, not everyone qualifies for an HSA, and not all employers offer one.

Some people have both an FSA and an HSA if their employer offers both and they are enrolled in a high-deductible plan. In that case, you can contribute to both accounts in the same year, but the combined total of FSA and HSA contributions cannot exceed the annual HSA limit set by the IRS. You also cannot use FSA money to reimburse yourself for expenses you already paid with HSA money.

If your employer offers only an FSA, or if you have a traditional health plan, you cannot open an HSA on your own — it must be offered through your employer or purchased through the health insurance marketplace.

How to enroll and what happens if you miss the window

You enroll in an FSA during your employer's open enrollment period, which is usually a two- to four-week window in the fall. Your employer sends information about the FSA plan, contribution limits, and how to enroll through your benefits portal or by mail. You choose your contribution amount and confirm your election.

If you miss open enrollment, you generally cannot enroll in an FSA until the next open enrollment period — unless you have a may have access to life event. may have access to events include losing health coverage, getting married or divorced, having a child, or a significant change in your dependent care costs. You must request enrollment within 30 to 60 days of the event (the exact window depends on your employer).

Once you enroll, your contribution amount is locked in for the full plan year. You cannot change it mid-year unless you have a may have access to life event. This is why estimating carefully during enrollment matters — you are committed to that amount for twelve months.

Common mistakes and how to avoid them

The most common mistake is overestimating how much you will spend and losing money at year-end. To avoid this, track your medical spending from the past year and add a small buffer for unexpected costs. If you are unsure, contribute less rather than more.

Another mistake is not submitting claims promptly. Some FSA administrators have deadlines for submitting claims — often 60 to 90 days after the end of the plan year. If you miss the deadline, you lose the reimbursement. Keep receipts and submit claims as soon as you have them.

A third mistake is using FSA money for ineligible expenses. If you submit a claim for something that does not may have access to, the administrator may deny it and you lose that money. Before you spend FSA funds on something you are unsure about, ask your administrator whether it qualifies.

Finally, some people forget they have FSA money left over and do not use it before the deadline. Set a reminder in November or December to review your balance and plan how to spend any remaining funds on may be able to access expenses before year-end.

Frequently Asked Questions

Can I use my FSA money for my spouse's medical expenses?

Yes, you can use FSA money to pay for medical expenses for yourself, your spouse, and your dependents — anyone you claim on your tax return. The money does not have to be used only for the person whose name is on the account.

What happens to my FSA money if I leave my job?

You lose access to any money remaining in your FSA account when you leave your job. You can continue to submit claims for expenses you incurred while employed, but only within the deadline set by your former employer's FSA administrator. Money you contributed but did not use is forfeited.

Can I get my FSA money back if I do not spend it?

No. The "use it or lose it" rule means forfeited money cannot be refunded to you. Some employers offer a grace period or small carryover, but most do not. This is why careful estimation of your expected medical spending is important when you enroll.

Do I need a prescription to buy over-the-counter medicine with my FSA?

Yes, as of 2020, you need a prescription from a doctor to use FSA money for over-the-counter medications. Exceptions include insulin, which you can buy without a prescription. Ask your doctor to write a prescription if you take over-the-counter medications regularly.

Can I use my FSA debit card everywhere?

FSA debit cards work at pharmacies, medical offices, and some other healthcare providers, but not everywhere. You cannot use it at a grocery store or general retailer, even to buy may be able to access items. If the card is declined, you can pay out of pocket and submit a claim for reimbursement instead.