Every December, millions of Americans lose money they already earned.
It happens because of a rule buried in a benefits portal most people never open until it's too late.
It's called the flexible spending account, or FSA, and it's one of the most useful tools in a paycheck — if you use it on time.
The catch: many plans require you to spend your balance by December 31, and anything left over typically goes back to your employer.
Here's how the deadline actually works, because it's more confusing than it should be.
Some employers offer a grace period that pushes your spending deadline to March 15.
Others offer a carryover, letting you roll a limited amount — the IRS caps it at $640 for 2025 — into the next year.
You have to check your own plan, because the rules vary company to company.
The good news is that FSA dollars are more flexible than most people realize.
You can spend them on eyeglasses, contact lenses, prescription sunglasses, and exams.
Bandages, heating pads, thermometers, blood pressure monitors, and first-aid kits usually qualify.
So do many over-the-counter medicines, menstrual products, and even some sunscreen if it meets the SPF requirement.
Insulin, diabetic supplies, and breast pumps are covered too.
If you're scrambling, the FSA Store and similar retailers label every item as eligible, which saves the guesswork.
Amazon and major pharmacies also flag FSA-eligible products in search results.
Just confirm you're buying from an eligible category before checking out — a random "health-adjacent" gadget may not count.
One smart move: schedule medical appointments now.
Copays, deductibles, dental cleanings, eye exams, and therapy sessions all count toward your balance.
Some plans let you prepay for services you'll use in January, effectively using this year's money for next year's care.
Then there's the dependent care FSA, a separate bucket many families forget.
It covers daycare, after-school programs, and summer day camp — up to $5,000 per household (or $2,500 if you're married filing separately).
If you've been paying a sitter or daycare out of pocket, you may have thousands sitting unused.
A quick warning about the "use it or lose it" trap: some employers let you submit claims for expenses incurred before the deadline even after December 31, as long as you file the paperwork in time.
Read your plan's run-out period, which is the window for submitting receipts.
Miss that, and a valid expense can still get denied.
Set a calendar reminder for the second week of December.
Log into your benefits portal, check your balance, and confirm whether your plan has a grace period, a carryover, or a hard cutoff.
Ten minutes of checking could save you hundreds. **The takeaway:** An FSA isn't free money — it's your money, taken out of your paycheck before taxes.
Final Thoughts
Treating the deadline like a real bill rather than a vague suggestion is the difference between a stocked medicine cabinet and a quiet donation to your employer's bottom line.