What Is an FSA? Flexible Spending Account Explained

If your employer offers a flexible spending account and you are not using it, you could be leaving hundreds, even thousands, of dollars in tax savings on the table. What is an FSA, exactly? It is a pre-tax savings account that lets you set aside money from your paycheck to pay for qualified medical expenses, effectively giving you a discount on healthcare equal to your marginal tax rate. The catch: most FSA funds must be used within the plan year, or a limited carryover, or you forfeit them. This guide is the plain-English explainer of how FSAs work, what they cover, and how to use yours wisely. For more on healthcare benefits and policy, explore our healthcare policy guide. This article is general information, not tax advice; confirm specifics with the IRS or a tax professional.

How a Flexible Spending Account Works

An FSA is an employer-sponsored benefit that allows you to contribute pre-tax dollars to pay for eligible out-of-pocket healthcare costs. During your employer’s open enrollment period, you elect an annual contribution amount. That money is deducted from your paychecks in equal installments throughout the year, before federal income tax, Social Security and Medicare tax (FICA), and most state income taxes are calculated. Because the money never counts as taxable income, you effectively pay for those healthcare costs at a discount.

Here is what makes FSAs unusual: your full annual election is available on day one of the plan year, even though you have not contributed all of it yet. If you elect $2,500 and have a $2,000 medical expense in January, you can use the FSA to cover it immediately, even though only one month’s worth of deductions has occurred. Your employer effectively fronts the difference. This “uniform coverage rule” is a significant advantage over an HSA, where you can only spend what you have actually deposited so far.

The primary types include a healthcare FSA (the most common, covering medical, dental, and vision expenses), a dependent care FSA (for childcare and certain elder-care expenses, with separate rules and limits), and a limited-purpose FSA (restricted to dental and vision, designed to be paired with an HSA). This article focuses on the healthcare FSA, the account most people mean when they ask “what is an FSA.”

FSA Contribution Limits and Tax Savings for 2026

For 2026, the IRS sets the maximum healthcare FSA contribution at approximately $3,400 per employee. Because the IRS adjusts this cap annually for inflation, the exact figure can shift year to year, so confirm the current-year number on IRS.gov or with your benefits administrator before you enroll. If both spouses have access to FSAs through their respective employers, each can generally contribute up to the maximum, potentially sheltering a larger combined amount from taxes. Employers may set lower limits than the IRS maximum, so check your plan documents.

The tax savings are straightforward and meaningful. Contributions avoid federal income tax, Social Security and Medicare tax (7.65% for most employees), and most state income taxes. For someone in the 22% federal bracket living in a state with a 5% income tax, every $1,000 contributed to an FSA can save roughly $340 or more in taxes. On a full contribution near the 2026 limit, that can add up to well over $1,000 in annual tax savings, money that would otherwise go to taxes. Your exact savings depend on your tax brackets and state, so treat these as illustrations rather than promises.

Unlike HSA contributions, FSA contributions cannot be deducted on your tax return if made outside of payroll; FSAs are exclusively employer-facilitated. Self-employed individuals and those whose employers do not offer FSAs cannot participate. According to IRS Publication 969, the contribution limit is adjusted annually for inflation, which is why the figure you see quoted online may lag the current plan year.

The Dependent Care FSA

A dependent care FSA is a separate account that helps working families pay for eligible childcare and certain adult or elder-care expenses so that you (and your spouse, if married) can work or look for work. It has its own annual contribution limit, which has historically been set at a fixed dollar amount rather than indexed to inflation like the health FSA, and it follows different eligibility rules. If you use daycare, after-school care, or similar services, ask your benefits administrator whether a dependent care FSA makes sense alongside your healthcare FSA, and verify the current limit for the plan year.

What Can You Spend FSA Money On?

The list of FSA-eligible expenses is extensive, and it was expanded by the CARES Act in 2020. Qualified expenses include doctor copays and coinsurance, prescription medications, over-the-counter drugs (including pain relievers, allergy medications, and cold remedies), dental care (cleanings, fillings, crowns, dentures, and orthodontics), vision care (eye exams, prescription glasses, contact lenses, and lens solution), mental health services, and physical therapy.

Since the CARES Act, menstrual care products (pads, tampons, and cups), sunscreen, first-aid supplies, and many over-the-counter medications no longer require a prescription to be eligible. Medical equipment such as blood pressure monitors, thermometers, crutches, and CPAP supplies also qualifies. Some less obvious eligible expenses include acupuncture, chiropractic care, hearing aids, fertility treatments, and smoking-cessation programs.

Expenses that are generally not eligible include cosmetic procedures, gym memberships (unless prescribed by a doctor for a specific condition), vitamins and supplements (unless prescribed), toiletries, and health insurance premiums. IRS Publication 502 provides the definitive list of qualifying medical expenses, and your FSA administrator’s website usually has a searchable eligibility tool when you are in doubt. Understanding your insurance deductible can help you estimate how much to set aside in your FSA for the year.

The “Use It or Lose It” Rule and Its Exceptions

The biggest drawback of FSAs is the forfeiture rule: unused funds at the end of the plan year are generally lost. This is fundamentally different from an HSA, where balances roll over indefinitely. However, employers may offer one of two relief provisions, but not both:

• Grace period: Up to an additional 2.5 months after the plan year ends to use remaining funds. If your plan year runs January through December, a grace period would give you until mid-March of the following year to incur expenses.
• Carryover: The ability to roll over a limited amount of unused funds into the next plan year, up to roughly $680 for 2026. This carryover cap is indexed annually for inflation, so verify the current figure with your plan.

Not all employers offer either provision, and many employees do not realize which option their plan includes. Check your plan documents during open enrollment. The forfeiture rule means careful planning is essential: contribute too much and you risk losing the excess; contribute too little and you miss out on tax savings. Reviewing your prior year’s medical expenses is a good baseline for your election.

Smart Strategies for Using Your FSA

Start by estimating your annual out-of-pocket medical expenses. Review the past year’s costs: copays, prescriptions, dental work, glasses, and any planned procedures. Add a small buffer for unexpected needs, but be conservative, because it is better to underestimate slightly than to lose money at year-end (beyond any carryover your plan allows).

Schedule routine appointments strategically. If you have remaining FSA funds late in the year, schedule dental cleanings, eye exams, or annual physicals before your deadline. Stock up on eligible over-the-counter items such as contact lens solution, first-aid supplies, sunscreen, and OTC medications. Many FSA-eligible retailers make last-minute spending easy.

Consider timing larger expenses. If you need new glasses, dental work, or orthodontics, plan these for a year when your FSA can offset the cost. For families, coordinate with your spouse’s FSA or benefits to maximize coverage. Keep all receipts, because your FSA administrator may request documentation for any reimbursement claim, and FSA usage must be substantiated.

FSA vs HSA: Key Differences

Both accounts save you money on healthcare through tax advantages, but they work quite differently, and mixing them up is one of the most common benefits mistakes. The most critical distinction: FSA funds generally expire at year-end (aside from a grace period or limited carryover), while HSA funds last indefinitely. An HSA requires a qualifying high-deductible health plan; an FSA works with most employer health plans. HSAs are individually owned and portable; an FSA is tied to your employer and is typically forfeited when you leave, though you can submit claims for expenses incurred before your departure.

HSAs also offer investment options for long-term, tax-advantaged growth; FSAs do not. On the other hand, an FSA gives you full-year availability from day one, so your entire election is accessible immediately, while HSA spending is limited to your current balance. For a detailed side-by-side comparison, see our HSA vs FSA guide.

Frequently Asked Questions

Can I change my FSA contribution mid-year?

Generally, no. FSA elections are locked in for the plan year once open enrollment closes. However, qualifying life events, such as marriage, divorce, the birth or adoption of a child, a spouse gaining or losing coverage, or a change in employment status, may allow a mid-year adjustment. Check with your HR department about what qualifies under your specific plan.

What happens to my FSA if I leave my job?

Typically, your FSA ends on your last day of employment or the end of that month, depending on the plan. You can submit claims for eligible expenses incurred before your termination date, but you generally lose access to any remaining balance. Some employers offer COBRA continuation for FSAs, but it is rarely cost-effective, since you would pay the full contribution plus an administrative fee without the pre-tax benefit.

Can I have both an FSA and an HSA?

Not a general-purpose healthcare FSA and an HSA at the same time. However, you can pair an HSA with a limited-purpose FSA (covering only dental and vision) or a post-deductible FSA. If you are deciding between the two, your health plan type usually determines which is available: high-deductible plans pair with HSAs, while traditional plans pair with FSAs.

Are FSA contributions subject to Social Security tax?

No. FSA contributions are excluded from FICA (Social Security and Medicare) taxes, which means you save an additional 7.65% beyond your income tax rate. HSAs share this advantage when contributions are made through payroll, but it is often overlooked when people calculate the true value of an FSA.

Is this the same as other “FSA” articles I have seen?

This page is the plain “what is an FSA” explainer, focused on how a healthcare flexible spending account works and how to use it. If you are looking for a specific year’s contribution figures or a deeper dive on a particular sub-topic, look for our dedicated pages on FSA limits and FSA account details, and always confirm current-year numbers with the IRS.

Sources

• Internal Revenue Service – Publication 969, Health Savings Accounts and Other Tax-Favored Health Plans (irs.gov)
• Internal Revenue Service – Publication 502, Medical and Dental Expenses (irs.gov)
• Internal Revenue Service – Annual inflation-adjustment guidance for FSA contribution and carryover limits (irs.gov)
• Healthcare.gov – Using a flexible spending account (FSA) (healthcare.gov)