What Is the FSA 'Use-It-or-Lose-It' Rule?
A flexible spending account behaves differently from most savings accounts in one important way: money left unspent at the end of the plan year doesn’t automatically carry forward, and in many cases it disappears entirely.
The short answer
The use-it-or-lose-it rule is a general requirement that unused flexible spending account funds be forfeited back to the employer’s plan at the close of the plan year, rather than rolling over indefinitely the way a typical savings account balance would. Employers are allowed, though not required, to soften that deadline with one of two optional features — a grace period or a carryover — but a single plan can only offer one of the two, never both at the same time.
Why the rule exists in the first place
An FSA is funded with pre-tax payroll contributions, part of the tax benefits that come with a flexible spending account, and that tax advantage comes with structural tradeoffs set by the rules governing these accounts, one of which is that the money is meant to be used for expenses within the plan year rather than accumulated the way retirement savings would be. Treating it as an annual use-it-or-lose-it benefit, rather than a long-term account, is part of what allows the pre-tax treatment to work the way it does.
The two ways employers can soften the deadline
A grace period
A grace period extends the window during which new expenses can be incurred and paid for with the previous year’s leftover balance, typically for a couple of months after the plan year technically ends. It doesn’t add new money — it just extends the deadline for spending what was already there.
A carryover
A carryover instead allows a limited portion of the unused balance to move directly into the next plan year’s account, available alongside whatever new contributions are made that year. The difference between these two approaches matters quite a bit for planning, since one extends time and the other preserves a capped amount of money.
Why a plan can only choose one
The rules governing these accounts don’t allow an employer to combine a grace period and a carryover in the same plan, so checking which one, if either, applies is a necessary first step rather than an assumption. Some employers offer neither, in which case the original use-it-or-lose-it deadline applies in full.
What happens to forfeited money
Funds that go unused and unprotected by either feature are forfeited back to the plan rather than returned to the employee, and they’re typically used to offset the administrative costs of running the plan for everyone enrolled in it.
Ways to avoid losing FSA money
- Check the plan’s specific rules early. Knowing whether a grace period, a carryover, or neither applies shapes how the rest of the year should be planned.
- Estimate predictable expenses in advance. Recurring costs, including those eligible under a dependent care FSA, are easier to plan around than unpredictable ones.
- Track the balance periodically. Waiting until the final weeks of the plan year to check a balance leaves little time to spend it down thoughtfully.
- Consider a limited-purpose version if paired with an HSA. A limited-purpose FSA follows the same forfeiture rule but applies it to a narrower set of eligible expenses.
The simplest way to think about it
The use-it-or-lose-it rule isn’t a penalty so much as a structural feature of how these accounts get their tax advantage, and the grace period and carryover options exist specifically to take some of the pressure off the calendar. Checking which, if either, a given plan offers is worth doing well before the plan year winds down rather than after.