Open enrollment season is here, and millions of Americans are about to click through the same benefits screen they rush past every year.
Two accounts sit side by side: the FSA and the HSA.
They sound nearly identical, and that similarity is exactly what makes them expensive.
An FSA, or flexible spending account, lets you set aside pre-tax dollars for medical costs, but there's a catch that trips up first-timers every single year.
The money generally has to be spent by December 31, with only limited carryover or a short grace period depending on your employer.
Miss the deadline, and the balance vanishes.
An HSA, or health savings account, works differently, and the gap is enormous.
You can only open one if you're enrolled in a high-deductible health plan, but the money rolls over indefinitely.
Spend it decades later on qualified medical costs, and withdrawals stay tax-free too.
It's the only account in the tax code with that triple advantage.
A 2024 report from the Employee Benefit Research Institute found that many HSA holders treat the account like a checking account, spending balances as bills arrive instead of letting them compound.
That habit can erase the single biggest benefit the account offers.
The contribution limits tell their own story.
For 2025, HSA holders can set aside up to $4,300 for individual coverage and $8,550 for family coverage, plus an extra $1,000 if you're 55 or older.
FSA limits sit at $3,300 per employer for 2025.
Both figures are adjusted annually for inflation, and the HSA ceiling keeps climbing.
If your employer offers a traditional PPO or HMO plan, you're locked out of an HSA entirely.
For people managing a chronic condition or expecting a baby, the lower deductible on a traditional plan can outweigh the tax perks.
But if you're young, relatively healthy, and your employer offers a high-deductible plan with an HSA, the math usually favors the HSA.
You keep the account even if you change jobs, which an FSA never allows.
One more wrinkle worth knowing: some employers now offer a limited-purpose FSA alongside an HSA, covering dental and vision only.
That combo lets you stack both accounts without disqualifying yourself from HSA eligibility.
Few workers know it exists, and even fewer ask HR about it.
The takeaway for open enrollment is simple.
Check which plan you're actually being offered before you assume either account is right for you.
Then decide whether you're funding next year's receipts or building a long-term medical fund. **Our take:** The FSA isn't a scam, but it punishes anyone who forgets a deadline or guesses their spending wrong.
Final Thoughts
If an HSA is available to you and you can afford to leave the money alone, choosing the FSA instead is one of the most expensive defaults in personal finance.