A Flexible Spending Account lets you set aside pre-tax money from your paycheck to pay for medical expenses your insurance doesn't cover

A Flexible Spending Account (FSA) is an employer-sponsored plan where you contribute money before taxes are taken out, then use that money to pay for may be able to access medical, dental, and vision costs. The money comes directly from your paycheck, so you avoid federal income tax, Social Security tax, and Medicare tax on those contributions. You decide how much to set aside each year—usually between $100 and $3,300, though the limit changes annually.

The catch is that FSAs operate on a "use it or lose it" rule: money you don't spend by the end of the plan year generally cannot be rolled over to the next year. Some employers offer a grace period of up to 2.5 months into the following year, or let you carry over up to $610 (the amount varies by year), but most do not. This means you need to estimate your medical spending fairly accurately when you enroll.

FSAs are different from Health Savings Accounts (HSAs) in one key way: you don't need a high-deductible health plan to have an FSA. Your employer straightforward has to offer one. Many people use FSAs alongside regular insurance plans to cover out-of-pocket costs like copays, deductibles, and expenses insurance won't pay for at all.

Key Takeaways

  • FSA contributions come from your paycheck before taxes, which reduces your taxable income and the amount you owe in federal and payroll taxes.
  • You can use FSA money for copays, deductibles, prescription medications, dental work, vision care, and certain medical supplies and equipment.
  • Money left unspent at the end of the plan year is forfeited unless your employer offers a grace period or carryover option.
  • You must enroll during your employer's open enrollment period, usually once a year, and your election stays in place for the entire plan year.
  • FSAs require you to submit receipts or explanation of benefits to prove expenses are may be able to access before the plan reimburses you.

What you can and cannot pay for with FSA money

FSA funds cover most medical, dental, and vision expenses that you pay out of your own pocket. This includes copays and coinsurance (your share of the cost after insurance pays), deductibles, prescription medications, and over-the-counter drugs like pain relievers and allergy medicine (though you need a prescription or doctor's note for some OTC items). Dental work—cleanings, fillings, root canals, orthodontia—and vision care like eye exams, glasses, and contact lenses all may have access to.

Medical equipment and supplies also count: hearing aids, crutches, blood glucose monitors, insulin, and certain home medical devices. Therapy copays, mental health visits, and physical rehabilitation are covered. Some less obvious expenses may have access to too: acupuncture, chiropractic care, and certain fertility treatments, depending on your plan's rules.

What doesn't work: cosmetic procedures (unless medically necessary), gym memberships, vitamins and supplements (unless prescribed by a doctor for a specific condition), and over-the-counter items like sunscreen or toothpaste. Health insurance premiums themselves cannot be paid from an FSA, though you can use FSA money for costs insurance doesn't cover.

How to claim reimbursement and what paperwork you need

When you incur an may be able to access expense, you pay for it out of pocket, then request reimbursement from your FSA plan. Most employers provide a debit card linked to your FSA account, which you can use at pharmacies, doctors' offices, and medical suppliers—the card automatically deducts from your FSA balance. If you use the card, keep your receipt anyway; the plan administrator may ask for proof later.

If you pay cash or use your personal credit card, you'll submit a claim form (usually available through your employer's benefits website or by mail) along with a receipt showing the date, amount, and what was purchased. For insurance-covered services, you can submit the Explanation of Benefits (EOB) from your insurance company instead of a receipt. Most plans process claims within one to two weeks.

Keep all receipts and EOBs for at least three years. The IRS can audit FSA claims, and your plan administrator may request documentation to verify that expenses were actually may be able to access. If you cannot produce proof, the reimbursement may be denied and you'll lose that money.

The "use it or lose it" rule and how to avoid wasting money

At the end of your plan year, any money you haven't spent is forfeited. You cannot carry it to the next year, request a refund, or transfer it to another account. This is a federal rule built into FSA law, and employers cannot override it—though they can offer a grace period or limited carryover as an alternative.

To avoid losing money, estimate your medical spending conservatively. Look at what you actually spent in the past year: copays for regular doctor visits, prescription refills, dental cleanings, and any one-time expenses you know are coming. If you wear contacts, need glasses, or have planned dental work, factor that in. If you're unsure, contribute a smaller amount rather than guessing high.

Some employers offer a grace period—usually 2.5 months into the next calendar year—during which you can spend down your previous year's FSA balance. Others allow you to carry over up to $610 (or the current year's limit) to the next year. Check your plan documents or ask your benefits administrator what option your employer offers. If neither applies, plan to spend your balance by December 31 or lose it.

When you can enroll and what happens if your life changes

You can enroll in an FSA only during your employer's open enrollment period, which typically happens once a year in the fall for coverage starting January 1. If you miss that window, you cannot enroll until the next open enrollment—there is no way around this rule.

However, certain life events let you enroll or change your election outside open enrollment. These include marriage, divorce, birth or adoption of a child, loss of other health coverage, a significant change in your spouse's benefits, or a change in your employer's plan. You usually have 30 to 60 days from the event to notify your benefits administrator and make changes. If you lose your job or your employer stops offering an FSA, you can use the remaining balance through the end of the plan year, but you cannot add new contributions.

If you have a major change in medical needs—a new diagnosis, a planned surgery, or a change in your family's health—you may be able to increase or decrease your FSA contribution mid-year, but only if your employer's plan allows it. Always check with your benefits department before assuming you can make a change.

How FSA contributions affect your taxes and take-home pay

When you contribute to an FSA, that money is deducted from your paycheck before federal income tax, Social Security tax, and Medicare tax are calculated. This means your taxable income is lower, so you pay less in taxes overall. The tax savings depend on your tax bracket, but for most people, contributing $2,500 to an FSA saves roughly $600 to $750 in taxes per year.

The tradeoff is that your take-home pay is reduced by the full amount of your FSA contribution. If you contribute $2,500 for the year, that's about $96 less per paycheck (assuming 26 pay periods). However, because you're saving on taxes, the actual reduction in your paycheck is smaller than the contribution amount. For example, if you're in the 24% tax bracket, a $2,500 contribution reduces your paycheck by roughly $1,900 after tax savings.

This makes FSAs most valuable if you know you'll have medical expenses anyway. You're essentially getting a discount on those expenses by paying with pre-tax dollars. If you contribute money you don't actually spend, you lose that discount and the money itself.

FSA vs. HSA: which one makes sense for your situation

An FSA and an HSA both let you set aside pre-tax money for medical expenses, but they work differently and have different rules. An FSA is available through your employer and does not require a high-deductible health plan; an HSA requires you to be enrolled in a high-deductible plan and can be opened through your employer or on your own. FSAs have the "use it or lose it" rule; HSAs let you carry money over indefinitely and even invest it for growth.

If your employer offers both, you cannot have both at the same time. If you have an HSA, you can have a limited-purpose FSA that covers only dental and vision expenses, but not general medical costs. Choose an FSA if you have predictable medical expenses each year and want to reduce your taxable income. Choose an HSA if you can afford to pay medical costs out of pocket and want to build a long-term savings account for healthcare.

If your employer offers only an FSA, it's still worth using if you know you'll have medical expenses. If your employer offers only an HSA and you're may be able to access, that's usually the better choice because you get the tax benefit without the risk of losing unspent money.

Frequently Asked Questions

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

You can continue to use your FSA balance through the end of the plan year, but you cannot add new contributions. After the plan year ends, any remaining balance is forfeited. You cannot transfer it to a new employer's FSA or to an HSA. If you're moving to a new job with an FSA, you'll need to enroll in that plan during open enrollment or within 30 days of a may have access to life event.

Can I use my FSA debit card at any store?

No. FSA debit cards work only at pharmacies, medical suppliers, doctors' offices, and other healthcare providers. They won't work at grocery stores or general retailers, even if those stores sell some items that might be may be able to access (like bandages). If you're unsure whether a specific store accepts FSA cards, call the number on the back of your card or check your plan's website.

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

For most OTC medications like pain relievers, allergy medicine, and cold medicine, yes—you need a prescription or a doctor's written note. Insulin is an exception and does not require a prescription. Check your plan documents or ask your administrator which OTC items your plan covers without a prescription.

Can I change my FSA contribution amount during the year?

Only if you have a may have access to life event like marriage, birth, adoption, loss of coverage, or a significant change in your family's health. Otherwise, your election is locked in for the entire plan year. If you realize you contributed too much or too little, you'll have to wait until next year's open enrollment to change it.

What if I submit a claim and it gets denied?

The plan administrator will send you a denial letter explaining why the expense was not may be able to access. You can appeal the decision by submitting additional documentation or a written explanation. If the appeal is denied, that money is lost and cannot be refunded. Keep detailed records of all claims and denials in case you need to dispute them later.