How a Flexible Spending Account Works and What You Can Buy With It

A Flexible Spending Account lets you set aside pre-tax money from your paycheck to pay for medical and dependent care costs

A Flexible Spending Account (FSA) is an employer-sponsored plan that lets you redirect a portion of your salary into a separate account before taxes are taken out. You then use that money to pay for medical expenses, dental care, vision care, or dependent care — and because the money went in before taxes, you pay less in federal income tax and payroll taxes overall.

The account is "flexible" because you choose how much to contribute each year (within IRS limits) and you decide how to spend it on covered expenses. Your employer does not control what you buy; you do. The money sits in an account managed by a third-party administrator, and you access it through a debit card, reimbursement forms, or direct payment to providers.

FSAs are different from Health Savings Accounts (HSAs) in one critical way: money you do not spend by the end of the plan year is forfeited. There is no rollover to next year, with rare exceptions. This "use-it-or-lose-it" rule means you need to estimate your expenses carefully before you commit.

Key Takeaways

• FSA contributions come from your paycheck before taxes, which lowers your taxable income and the taxes you owe.
• You can use FSA money for copays, deductibles, prescriptions, dental work, vision care, and dependent care — but not for insurance premiums or over-the-counter items without a prescription.
• Money left unspent at the end of the plan year is lost; you cannot carry it forward to the next year in most cases.
• You enroll in an FSA during your employer's open enrollment period, usually once per year, and your contribution amount is locked in for the full year.
• FSAs are only available through employers; you cannot open one on your own.

How much you can contribute and when enrollment happens

The IRS sets an annual contribution limit for FSAs. This limit changes year to year, so you should check your employer's plan documents or the IRS website for the current year's cap. Your employer may also set a lower limit, so confirm the maximum with your benefits team.

You enroll during your employer's open enrollment period, which typically occurs once per year in the fall or early winter. During this window, you choose your contribution amount for the following calendar year. Once you lock in your amount, you cannot change it unless you experience a may have access to life event — marriage, birth of a child, loss of other health coverage, or significant change in dependent care costs. A job change or salary increase alone does not may have access to.

Your contributions are deducted from your paycheck in equal amounts throughout the year. If you contribute $2,400 annually, your employer deducts roughly $200 from each monthly paycheck (before taxes are calculated).

What expenses you can and cannot pay for with FSA money

FSA funds cover a wide range of medical, dental, vision, and dependent care costs. You can use the money for copays and coinsurance, deductibles, prescription medications, dental cleanings and fillings, eyeglasses and contact lenses, hearing aids, and dependent care (childcare or adult daycare for an elderly parent). Over-the-counter items like pain relievers, allergy medicine, and cold remedies are covered only if you have a prescription from a doctor.

FSA money does not cover health insurance premiums, long-term care insurance, or cosmetic procedures. It also does not cover gym memberships, vitamins without a medical reason, or most wellness programs. The IRS maintains a detailed list of covered and non-covered items; when in doubt, ask your plan administrator before you spend.

Dependent care FSAs have their own rules. These accounts pay for childcare, preschool, and adult daycare for a dependent you claim on your taxes. They do not cover overnight camps, tuition for kindergarten and above, or care provided by a spouse or dependent.

How to access your FSA money and submit claims

Most FSAs issue a debit card that you can swipe at pharmacies, doctor offices, and vision centers. The card is linked to your account balance, and the transaction is deducted immediately. Some providers, especially dental offices, may not accept the FSA card, so you will need a backup method.

If your provider does not accept the card, you can pay out of pocket and then submit a claim for reimbursement. You will need to provide a receipt showing the date, amount, provider name, and what was purchased. Your plan administrator has a website or mobile app where you can upload receipts and request reimbursement. Processing typically takes one to two weeks.

Keep all receipts and documentation. The IRS requires that FSA administrators verify expenses are legitimate, and you may be asked to prove that a charge was for a covered service. If you cannot provide proof, you may have to repay the reimbursement.

The use-it-or-lose-it rule and the grace period

Any money remaining in your FSA at the end of the plan year is forfeited. You cannot roll it over to the next year, and you cannot transfer it to another account. This rule exists because FSAs are tax-advantaged accounts; the IRS does not allow you to accumulate unlimited pre-tax money indefinitely.

Some employers offer a grace period of up to two and a half months into the next calendar year. During this time, you can continue to spend down your previous year's balance. Not all employers offer this, so check your plan documents. A few employers also offer a carryover option that lets you roll up to $610 (the amount varies by year) into the next year, but this is uncommon.

Because of this rule, estimate conservatively. If you think you will spend $1,500 in medical costs next year, contribute $1,500 or slightly less. Overestimating means you lose money; underestimating means you miss out on the tax savings.

FSA versus HSA: when each makes sense

An FSA and an HSA both offer tax advantages, but they work differently and have different rules. An FSA is available through any employer plan. An HSA is only available if you are enrolled in a high-deductible health plan (HDHP), and you must open it yourself through a bank or investment firm.

FSA money must be spent within the plan year or it is lost. HSA money rolls over indefinitely and can be invested like a retirement account. If you have predictable medical expenses each year, an FSA makes sense. If you want to save for future medical costs or have variable expenses, an HSA is more flexible.

Some employers offer both plans. If you are in an HDHP, you can contribute to an HSA but not an FSA. If you are in a traditional health plan, you can contribute to an FSA but not an HSA. Check with your benefits team about which plans are available to you.

Common mistakes to avoid when using an FSA

The biggest mistake is overestimating expenses and losing money at year-end. Before you enroll, review your medical bills and prescriptions from the past year. Add in any planned expenses like dental work or vision exams. Be honest about what you will actually spend, not what you might spend in a worst-case scenario.

Another common error is buying over-the-counter items without a prescription. Many people assume they can use FSA money for any health-related purchase, but the IRS is strict: most OTC items require a doctor's prescription to may have access to. Ask your doctor to write a prescription for items you use regularly, like allergy medicine or pain relievers.

Do not assume your FSA card will work everywhere. Some providers, especially small dental practices or independent vision centers, do not accept FSA cards. Have a plan to pay out of pocket and submit a claim if needed. Keep receipts organized in one place so you can find them quickly if your administrator asks for proof.

Frequently Asked Questions

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

You forfeit any unused balance in your FSA when you leave your employer. The money does not follow you to a new job. Some employers allow you to continue spending down your balance for a short period after you leave, but this is not may provide. If you are planning to leave your job, try to spend your FSA balance before your last day.

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

Yes, as long as you claim them as dependents on your tax return. You can use FSA money for any dependent's copays, prescriptions, dental work, and vision care. The money does not have to be spent on the person whose name is on the account.

Do I need receipts to use my FSA debit card?

When you swipe the FSA debit card at a pharmacy or doctor's office, the transaction is usually verified automatically because the merchant is coded as a medical provider. However, some administrators may ask for a receipt after the fact to confirm the expense was covered. Keep receipts for at least three years in case you are audited.

Can I change my FSA contribution amount mid-year?

No, unless you have a may have access to life event. Marriage, birth of a child, loss of health coverage, or a significant change in dependent care needs all may have access to. A raise or change in your medical expenses does not. If you make a mistake during enrollment, contact your benefits team immediately — some employers allow a short correction window.

What if I spend more than my FSA balance?

You cannot spend more than you have contributed. If your balance is $1,200 and you try to use the card for a $1,500 dental procedure, the transaction will be declined for the amount over your balance. You will need to pay the difference out of pocket or reschedule the procedure.