Roughly 35 million American households set aside money in a flexible spending account this year, and a big chunk of them are about to forfeit whatever is left in it.
If you have an FSA through work, the December 31 deadline is the one date on the calendar that actually costs you real cash.
Miss it, and the balance doesn't roll into your checking account — it goes back to your employer.
Say you elected $2,000 for the year and have $600 sitting there.
That's $600 you already earned and set aside, and it disappears unless you spend it on eligible expenses before the clock runs out.
For a household watching grocery bills and rent climb, that's not a rounding error.
Two quirks buy you extra time, but only if your plan offers them.
A grace period pushes your deadline to March 15 of next year.
A carryover lets you roll a limited amount — $640 for 2025 plans — into the next year.
You don't get to pick these; they're written into your employer's plan document, so check your benefits portal or call HR before assuming you have either one.
The good news is the eligible expense list is wider than most people think.
Prescription glasses, contacts, and sunglasses with a prescription all qualify.
So do dental cleanings, fillings, and crowns, plus copays for doctor visits and prescriptions.
Less obvious items include bandages, heating pads, thermometers, blood pressure monitors, and even some acne treatments and sunscreen, depending on whether your plan follows the CARES Act expansion.
Contact lens solution, first aid kits, and over-the-counter pain relievers are reimbursable at many employers now.
Buying next year's supply in December is a legitimate way to zero out a balance instead of losing it.
One warning: don't panic-swipe the card on things that don't qualify.
An FSA debit card will decline ineligible purchases, but if a claim gets denied after the fact, you may have to repay the money — and some employers charge a penalty on top.
The IRS also allows an audit of your claims, so documentation matters.
If you're still staring at a balance with days to go, book a dental cleaning, order replacement glasses, or schedule that eye exam you've been putting off.
Providers often have same-week openings in late December as people race the same deadline.
Then submit the claim through your FSA portal immediately — reimbursements can take a few weeks to process, and the expense date, not the submission date, is usually what counts.
The takeaway is simple: this is one deadline where doing nothing has a price tag.
Spend twenty minutes checking your balance and your plan's rules, and you'll either use the money or confirm you have a grace period to fall back on.
Final Thoughts
Either way, you'll know before January 1 whether you're leaving hundreds of dollars on the table.