A Flex 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 decide how much money to contribute from your salary before taxes are taken out. That money sits in an account you control, and you withdraw it to pay for may be able to access medical costs — copays, deductibles, prescriptions, dental work, vision care, and other out-of-pocket expenses. Because the money comes out before federal income tax, Social Security tax, and Medicare tax are calculated, you reduce your taxable income for the year.

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 (usually December 31) is forfeited. 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 your medical expenses accurately before you commit to a contribution amount.

Key Takeaways

  • You contribute pre-tax money through payroll deduction, which lowers your taxable income and the taxes you owe that year.
  • You can only enroll in an FSA during your employer's open enrollment period, or within 30 to 60 days of a may have access to life event such as marriage, birth, or loss of health coverage.
  • Money you don't spend by the end of the plan year is forfeited unless your employer offers a grace period or carryover option.
  • You access FSA funds by submitting receipts to your plan administrator, using a debit card linked to the account, or requesting reimbursement after you pay out of pocket.
  • FSA contributions reduce your federal income tax, Social Security tax, and Medicare tax, but the account is separate from your health insurance plan.

How much you can contribute and when enrollment happens

For 2024, the maximum FSA contribution is $3,200 per year (this limit changes annually). You choose your contribution amount during your employer's open enrollment period, which typically occurs once a year in the fall for coverage starting January 1. Your employer deducts your chosen amount evenly from each paycheck throughout the year.

You can only change your contribution outside of open enrollment if you experience a may have access to life event: marriage, divorce, birth or adoption of a child, death of a spouse or dependent, loss of health coverage, significant change in your spouse's health plan, or a change in your employer's plan. You have 30 to 60 days (depending on your employer) to notify your benefits administrator and adjust your contribution. If you don't make changes during open enrollment or after a may have access to event, you're locked into your current contribution for the entire year.

What expenses you can pay for with FSA money

FSA funds cover a broad range of medical expenses, but not everything. may be able to access expenses include copays and coinsurance, deductibles, prescription medications, insulin, dental work (cleanings, fillings, root canals, orthodontia), vision care (eye exams, glasses, contact lenses), hearing aids and batteries, medical equipment (crutches, wheelchairs, blood pressure monitors), and over-the-counter medications (only if you have a prescription from your doctor). Feminine hygiene products became may be able to access in 2020.

Ineligible expenses include health insurance premiums, cosmetic procedures, vitamins and supplements (unless prescribed), gym memberships, and over-the-counter items without a prescription. The IRS maintains a detailed list, and your plan administrator can tell you whether a specific expense qualifies. If you submit a receipt for an ineligible expense, the plan will deny reimbursement and you'll owe the money back.

How you access and spend FSA money

There are three main ways to use your FSA. First, many employers issue a debit card linked to your FSA account. You swipe it at the pharmacy, doctor's office, or medical supplier just like a regular debit card, and the cost is deducted from your FSA balance. The merchant must be coded as a medical provider for the card to work.

Second, you can pay out of pocket and then request reimbursement. You submit your receipt and a claim form to your plan administrator (usually online through a website or mobile app), and they send you a check or direct deposit within one to two weeks. Third, some providers (like your doctor's office or pharmacy) can bill your FSA directly if they're set up to do so — you authorize them to charge your account, and they handle the paperwork.

Keep all receipts and documentation. Your plan administrator may ask for proof that an expense was medical and that you actually paid it. If you can't provide a receipt, the reimbursement may be denied.

The "use it or lose it" rule and what happens to unspent money

Money remaining in your FSA at the end of the plan year is forfeited — you cannot roll it over to the next year or withdraw it as cash. This is the most important limitation of FSAs. If you contribute $2,500 and spend only $1,800, the remaining $700 is lost. This rule exists because FSAs are tax-advantaged accounts; the IRS does not allow you to carry forward unused pre-tax money.

Some employers offer a grace period of up to 2.5 months after the plan year ends (so through mid-March if your plan year ends December 31). During the grace period, you can still submit claims for expenses you incurred during the previous plan year. Other employers allow you to carry over up to $610 of unused funds into the next year (this amount is adjusted annually). A few employers offer both. Check your plan documents or ask your benefits administrator which option, if any, your employer provides.

How FSA contributions affect your taxes

FSA contributions reduce your taxable income, which means you pay less federal income tax, Social Security tax, and Medicare tax. If you contribute $2,500 to an FSA and earn $50,000 per year, your taxable income drops to $47,500. The tax savings depend on your tax bracket; someone in the 22% federal tax bracket saves about $550 in federal tax alone on a $2,500 contribution, plus additional savings from reduced Social Security and Medicare taxes.

However, FSA money is not "free" — you're using money you would have earned anyway. The benefit is that you avoid paying taxes on the portion you set aside for medical expenses. This is different from a Health Savings Account (HSA), which also allows tax-free contributions but lets you carry money forward indefinitely and withdraw it tax-free in retirement for any reason after age 65.

FSA vs. other tax-advantaged medical accounts

FSAs are often confused with Health Savings Accounts (HSAs) and Dependent Care FSAs, but they work differently. An HSA requires you to be enrolled in a high-deductible health plan (HDHP), allows you to carry money forward year to year, and lets you invest the balance. An FSA is available regardless of your health plan type, requires you to spend money each year or lose it, and is typically held in a cash account. A Dependent Care FSA is a separate account for childcare and elder care expenses, with a lower annual limit ($5,000 for most filers in 2024) and its own set of may be able to access expenses.

You cannot have an FSA and an HSA in the same year, though you can have an FSA and a Dependent Care FSA together. If your employer offers an HSA, compare the two: HSAs offer more flexibility and long-term savings, but FSAs may make sense if you have predictable medical expenses each year and want when ready tax savings.

Frequently Asked Questions

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

Your FSA ends when your employment ends, and you forfeit any unused balance. Some employers allow a short window (usually 30 to 60 days) to submit claims for expenses you incurred before you left. You cannot transfer FSA money to another account or take it with you. If you move to a new job with an FSA, you start fresh with a new account and new contribution amount.

Can I change my FSA contribution amount during the year?

Only if you experience a may have access to life event such as marriage, birth, adoption, divorce, death of a dependent, loss of health coverage, or a significant change in your spouse's plan. You must notify your employer's benefits administrator within 30 to 60 days of the event. Outside of these circumstances and open enrollment, your contribution is locked in for the year.

Do I need receipts to prove my FSA expenses?

Yes. Your plan administrator may request receipts, invoices, or explanation of benefits to verify that an expense was medical and that you paid it. Keep all documentation for at least three to five years. If you use a debit card and the merchant is coded as medical, you may not need to submit a receipt when ready, but you should keep it in case the plan asks for verification later.

Can I use my FSA debit card at any pharmacy or doctor's office?

Only at providers coded as medical merchants in the payment system. Some pharmacies, doctor's offices, and medical suppliers accept FSA cards; others do not. If a merchant is not set up to accept FSA payments, you'll need to pay out of pocket and request reimbursement. Your plan administrator can tell you which providers in your area accept FSA debit cards.

What if I overestimate my medical expenses and have money left over?

Any balance remaining at the end of the plan year is forfeited unless your employer offers a grace period or carryover. To avoid losing money, estimate conservatively based on your past medical spending and known upcoming expenses. If you're unsure, contribute a smaller amount — you can always increase it during the next open enrollment period.