There's a deadline on your calendar that has nothing to do with taxes and everything to do with money you've already earned.
If you set aside money in a flexible spending account through your job, that balance doesn't roll over the way a 401(k) does.
In many plans, whatever is left when the clock runs out simply vanishes.
That's the "use it or lose it" rule, and it's baked into how FSAs work.
You decide during open enrollment how much to withhold from each paycheck, pre-tax, for the year ahead.
Spend it on eligible expenses and you come out ahead.
Guess wrong and you're donating that cash to your employer's bottom line.
Most plans tie the deadline to the end of the calendar year, but the fine print matters.
Your employer may offer a grace period of up to 2.5 months into the next year, or allow a carryover of a limited amount — the IRS sets the cap and adjusts it annually.
You won't know which camp you're in unless you read your plan documents or call HR.
The eligible expense list is longer than most people assume, which is exactly why balances go unused.
Beyond doctor visits and prescriptions, you can often use FSA funds for eyeglasses, contact lenses, dental work, hearing aids, bandages, thermometers, and certain menstrual products.
Some plans cover sunscreen and first-aid kits.
A quick check of the IRS list or your plan's app before the deadline can turn a forgotten balance into a stocked medicine cabinet.
Here's the catch that trips people up: you generally can't use FSA money on over-the-counter medicine without a prescription, though rules have loosened in recent years for some items.
And if you're enrolled in a dependent care FSA, that's a separate pot with its own rules and its own deadline.
A purchase made on the last day of the plan year counts, but a reimbursement claim submitted weeks later may not.
Keep your receipts and submit claims early rather than gambling on a grace period you're not sure exists.
If you're staring down a balance you can't spend in time, booking a dental cleaning, refilling a prescription, or ordering replacement glasses before the cutoff is a common move.
Just don't buy things you'll never use solely to avoid "wasting" the money — spending a dollar to save forty cents isn't a win.
The takeaway is simple: the FSA deadline rewards people who plan and quietly punishes people who don't.
Set a reminder for early December, log into your account, and check the balance before the year slips away.
Final Thoughts
A few minutes now beats finding out in January that your money already expired.