Simple definition
A flexible spending account, or FSA, is an account offered through your employer that lets you set aside money from your paycheck before taxes to pay for eligible medical or dependent care costs. Think of it as a labeled envelope filled with pre-tax dollars. Because the money skips taxes, you stretch it further — but you generally have to use it within the plan year.
Why it matters
An FSA lowers your taxable income while helping you cover predictable health or dependent care costs with pre-tax dollars. The catch is the use-it-or-lose-it rule, so estimating your spending carefully matters — set aside too much and you could forfeit the leftover.
Real-life example
Suppose you expect $1,200 in dental and vision costs next year and elect to put that into a health FSA. That $1,200 comes out of your pay before taxes, so you avoid paying income tax on it. You then use the account to reimburse those costs as they come up during the plan year.
Common mistakes
- Overfunding the account and forfeiting money you could not spend in time.
- Confusing an FSA with an HSA — the rules and rollover options are different.
- Forgetting the use-it-or-lose-it deadline and losing the remaining balance.
- Not saving receipts, then struggling to prove an expense was eligible.
Pro tips
- Estimate your predictable costs before choosing how much to set aside.
- Ask your employer whether the plan offers a grace period or small carryover.
- Keep receipts for every FSA purchase in case you need to substantiate it.
- Spend down the balance before year-end so you do not forfeit leftover funds.
Related Money Dictionary terms
- Health Savings Account (HSA)A tax-advantaged account for medical costs, paired with a high-deductible health plan, offering strong tax benefits.
- Pre-Tax ContributionMoney put into an account before taxes are applied, lowering your taxable income now and taxed on withdrawal later.
- Tax-Advantaged AccountAn account offering tax breaks on contributions, growth, or withdrawals to encourage saving for goals like retirement.
- DependentA qualifying child or relative you support financially, which can unlock deductions and credits on your return.
- WithholdingMoney your employer takes out of each paycheck and sends to the government toward your expected tax bill.
Frequently asked questions
What is the difference between an FSA and an HSA?
Both use pre-tax money for health costs, but an FSA is employer-owned and generally must be used within the plan year, while an HSA is yours to keep and rolls over indefinitely. HSAs require a high-deductible health plan. FSAs do not, but they come with stricter use-it-or-lose-it rules.
What happens to unused FSA money?
Under the use-it-or-lose-it rule, money left in a health FSA at the end of the plan year is generally forfeited. Some employers offer a short grace period or allow a small amount to carry over. Check your specific plan, and try to estimate your contribution so little is left behind.
How much can I put in an FSA?
The IRS sets an annual limit on health FSA contributions, and it can change from year to year. Dependent care FSAs have a separate limit. Because the figures are adjusted over time, check the current IRS amount and your employer's plan details when you decide how much to elect.
Knowing what Flexible Spending Account (FSA) means is knowledge — the first half. A brick gets placed when you act on it: estimate next year's predictable medical costs before choosing your FSA amount.
Also builds: Health Insurance & Healthcare Costs
Sources & references
More in Taxes
Plain-English education — not personalized legal, tax, or investment advice.