What is a Flexible Spending Account (FSA)?
A Flexible Spending Account (FSA) is a US employer-sponsored, payroll-funded account under Internal Revenue Code section 125 that lets employees set aside pre-tax dollars for qualified medical, dental, vision, or dependent-care expenses. Contributions reduce federal income tax, FICA, and most state income tax, but the account is subject to a strict use-it-or-lose-it rule by plan year-end with a limited $680 carryover or 2.5-month grace period under 2026 rules.
Detailed definition
The Flexible Spending Account traces back to the Revenue Act of 1978, which added Internal Revenue Code section 125 and authorized cafeteria plans. Treasury regulations issued in 1984 and refined in proposed rules from 2007 established the modern FSA structure. The account is sponsored by the employer, administered by a third party (HealthEquity, WageWorks, Optum, and dozens of smaller firms run the market), and funded through pre-tax payroll deductions inside a Section 125 plan.
Two main flavors exist. The Health FSA pays for qualified medical, dental, and vision expenses under the same IRS Publication 502 definition that governs HSAs. The Dependent-Care FSA pays for daycare, after-school programs, before-school care, and certain elder-care expenses for tax dependents while a parent works. A third subtype, the limited-purpose FSA, covers dental and vision only and can be paired with an HSA.
The defining trade-off is the use-it-or-lose-it rule. Any balance unused by the end of the plan year (plus grace period if offered, or carryover up to $680) is forfeited back to the employer. This forces employees to estimate spending tightly at enrollment, and to ramp up December-only purchases (extra dental visits, new glasses, prescription refills) if they realize they have over-elected. The trade-off in exchange is uniform coverage: the full annual election is available January 1, so a January medical emergency that exceeds your year-to-date payroll deductions is still fully reimbursable.
2026 limits and how the tax saving works
2026 limits (IRS Rev. Proc. 2025-32 for health FSA): Health FSA per employee $3,400 Health FSA carryover up to $680 (if plan adopts it) Dependent-care FSA household $5,000 (MFJ, single, HoH) Dependent-care FSA MFS $2,500 Tax saved = Election x (Federal marginal + FICA 7.65% + State marginal) Example at 22% federal, 5% state: $3,400 x 34.65% = $1,178 saved
- Federal income tax saved: at your marginal bracket (10 to 37 percent in 2026).
- FICA saved: 6.2 percent Social Security up to $176,100 wage base in 2026, plus 1.45 percent Medicare with no cap, totaling 7.65 percent.
- State income tax saved: most states honor the federal Section 125 exclusion; the exceptions are New Jersey (state taxes FSA), Pennsylvania (state taxes some FSAs), and California (state taxes dependent-care but not health FSA).
- Plan choice: an employer must pick carryover OR grace period in advance; the IRS does not allow both, and dependent-care FSAs cannot have a carryover at all.
Worked example
Take a worker who elects $3,400 to a 2026 health FSA. She is in the 22 percent federal bracket and lives in a state with 5 percent income tax. The election is run through a Section 125 cafeteria plan via payroll deduction.
- FSA election: $3,400 (the 2026 maximum).
- Federal income tax saved: $3,400 x 22 percent = $748.
- FICA saved: $3,400 x 7.65 percent = $260.
- State income tax saved: $3,400 x 5 percent = $170.
- Total tax savings: $748 + $260 + $170 = $1,178.
FSA vs HSA
Both accounts pay for medical expenses with pre-tax money, but rollover behavior, eligibility, and investment options diverge sharply.
| Feature | Health FSA | HSA |
|---|---|---|
| 2026 contribution limit | $3,400 per employee | $4,400 self / $8,750 family (+$1,000 catch-up 55+) |
| Eligibility | Any employer-sponsored health plan | Requires HSA-eligible HDHP |
| Rollover | Up to $680 in 2026 OR grace period 2.5 months, employer's choice; rest is forfeited | Unlimited, indefinite |
| Portability | Forfeited at job loss (COBRA election excepted) | Belongs to employee, follows job changes |
| Investment | Not allowed | Allowed; ETFs / mutual funds above cash threshold |
| Funding at year start | Full annual election available January 1 | Only payroll-deducted amounts available so far |
| After age 65 non-medical use | Not allowed | Ordinary income, no penalty |
| Best for | Predictable annual medical spending | Long-term wealth building, retirement healthcare |
Related terms
Related calculators on 3Tej
Model your own FSA tax saving or compare directly against an HSA at your marginal bracket:
Frequently asked questions
What is the 2026 FSA contribution limit?
For 2026, IRS Revenue Procedure 2025-32 set the health FSA employee contribution limit at $3,400, with a $680 carryover allowed for plans that adopt it. The dependent-care FSA limit is $5,000 per household ($2,500 if married filing separately), unchanged since 1986 because that figure is not indexed for inflation.
Do FSA funds roll over to next year?
Health FSAs may allow either a $680 carryover for 2026 OR a 2.5-month grace period after plan-year end, but never both, and only if the employer adopts the option. Dependent-care FSAs are not allowed to carry over at all; everything unspent by year-end (plus grace period if offered) is forfeited to the employer. Always check your plan documents before assuming a rollover.
Can I have an HSA and an FSA at the same time?
A general-purpose health FSA disqualifies you from HSA contributions because it counts as other non-HDHP coverage. The workaround is a limited-purpose FSA (dental and vision only) or a post-deductible FSA, both of which can be paired with an HSA. Spouse's FSA also counts: if your spouse has a general-purpose health FSA at their employer, you lose HSA eligibility even if you do not enroll.
Is an FSA pre-tax for FICA as well as income tax?
Yes. FSA contributions made through a Section 125 cafeteria plan avoid federal income tax, the 6.2 percent Social Security tax, the 1.45 percent Medicare tax, and most state and local income taxes. Combined tax savings typically run 30 to 40 percent for most workers, making the FSA one of the most efficient ways to pay for predictable medical or childcare expenses.
When can I access my FSA money?
Health FSAs are uniformly pre-funded under IRS rules: the full annual election is available on January 1 (or the first day of plan coverage), even though contributions are deducted from each paycheck over the year. Dependent-care FSAs only allow reimbursement up to the cumulative amount contributed by payroll deduction so far, a key difference.
What happens to my FSA if I leave my job mid-year?
For health FSAs, unspent funds are typically forfeited unless you elect COBRA continuation of the FSA at your former employer. The election is only worthwhile if you have a large unspent balance and known upcoming expenses. Dependent-care FSAs are not subject to COBRA and the balance is lost on the date of separation. You can also claim qualifying expenses incurred up to the date of separation.
Sources and further reading
- IRS Revenue Procedure 2025-32 (October 2025) - official 2026 health FSA contribution limit ($3,400), carryover ($680), and related cafeteria-plan figures.
- IRS Publication 969 (2025) Health Savings Accounts and Other Tax-Favored Health Plans - rules for health FSAs and HSA / FSA interaction.
- IRS Publication 503 (2025) Child and Dependent Care Expenses - dependent-care FSA reimbursable expenses, the $5,000 cap, and credit interaction.
- IRS Notice 2013-71 (and Notice 2020-29, 2020-33) - the carryover-vs-grace-period rule and pandemic-era extensions.
- Society for Human Resource Management (SHRM) annual benefits survey - market data on what fraction of employers offer carryover vs grace period.