If you have a flexible spending account, the clock is quietly working against you.
Unlike its cousin the health savings account, an FSA typically comes with a use-it-or-lose-it rule that can wipe out whatever you don't spend by year-end.
That's real money vanishing from your paycheck — and most workers don't realize how much is at stake until December.
The two accounts look similar on the surface, but they behave nothing alike.
An FSA is funded with pre-tax dollars you elect during open enrollment, and for 2024 the IRS caps contributions at $3,200.
An HSA, by contrast, is only available if you're enrolled in a high-deductible health plan, and it lets you contribute up to $4,150 for individual coverage or $8,300 for family coverage.
The HSA limit for 2025 rises to $4,300 individual and $8,550 family.
The bigger difference is what happens to your balance.
FSA funds generally must be spent by the plan year's end, though many employers offer a grace period of up to two and a half months or allow you to roll over up to $640 in 2024.
HSA money, on the other hand, never expires.
It rolls over year after year, earns interest, and can even be invested in the stock market once your balance crosses a certain threshold, often $1,000 or so.
There's another wrinkle that catches people off guard.
HSAs are triple tax-advantaged — contributions go in pre-tax, growth is tax-free, and withdrawals for qualified medical expenses come out tax-free.
FSA dollars are also pre-tax, but they don't grow, and you can't take them with you if you switch jobs mid-year.
Your HSA follows you for life, even into retirement, where it can be used to cover Medicare premiums and other costs.
If your employer only offers a traditional PPO, an FSA may be your only pre-tax option — just be conservative with your election and track receipts carefully.
If you're on a high-deductible plan, an HSA is usually the stronger long-term play, especially if you can afford to pay current medical bills out of pocket and let the account compound.
One more caution: both accounts come with strict rules about what counts as a qualified expense.
Over-the-counter medicines generally require a prescription for FSA reimbursement, while HSA rules are slightly more flexible.
And the penalties for misuse are steep — non-qualified HSA withdrawals get taxed as income plus a 20% penalty before age 65.
Don't let an FSA deadline sneak up on you, and don't overlook an HSA if you're eligible.
Final Thoughts
A few minutes of planning now can mean hundreds of dollars staying in your pocket instead of evaporating at midnight on December 31.