An FSA is worth it if you spend money on medical, dental, or vision care that you would pay for anyway, and you can predict roughly how much you'll spend in the next year

The math is straightforward: an FSA lets you set aside pre-tax money for healthcare costs, which means you avoid federal income tax, Social Security tax, and Medicare tax on that money. If you're in the 22% federal tax bracket and your employer withholds 7.65% for payroll taxes, you're looking at roughly 30% in combined taxes. On $2,500 set aside in an FSA, that's about $750 you don't pay in taxes. That's real money back in your pocket.

But an FSA only works if three things are true: you actually have predictable healthcare expenses, you can afford to lock that money away for the year, and you're comfortable with the "use it or lose it" rule that applies to most FSAs. If any of those conditions don't fit your situation, an FSA can cost you money instead of saving it.

Key Takeaways

  • An FSA saves you money only if you spend that amount on medical, dental, or vision care regardless — the tax savings are real, but only on money you were going to spend anyway.
  • You must be able to predict your healthcare costs within a reasonable range, because money left unspent at the end of the year is forfeited under the standard "use it or lose it" rule.
  • If you have a high-deductible health plan paired with a Health Savings Account (HSA), an FSA may not be allowed, and an HSA usually offers better long-term value.
  • FSAs work best for people with regular, known expenses like ongoing prescriptions, routine dental work, or regular vision care.
  • The contribution limit changes yearly; for 2024 it is $3,200, and your employer may also contribute, which increases your tax savings.

When the tax savings actually matter

The tax benefit only applies to money you contribute yourself. If you set aside $2,500 in an FSA and spend $2,500 on may be able to access expenses, you save taxes on that $2,500. The amount you save depends on your tax bracket and whether you pay self-employment tax, but for most people it's between 25% and 35% of the amount contributed.

This matters most if you have predictable, recurring expenses. Someone taking a daily prescription medication, getting regular dental cleanings and fillings, or buying contact lenses every few months can estimate their costs fairly accurately. Someone who rarely sees a doctor and has no dental work planned should not contribute to an FSA, because the tax savings only apply to money you actually use.

If your employer contributes to your FSA as part of your benefits package, that's additional money you don't have to contribute yourself, and it's still tax-free when you spend it on may be able to access care. That increases the value of the FSA significantly.

The "use it or lose it" rule and how to work around it

Under the standard FSA rules, money you don't spend by the end of the plan year is forfeited — you lose it. This is the biggest risk of an FSA. If you contribute $2,500 and only spend $1,800, that $700 is gone. You don't get it back, and you don't roll it over to next year.

Some employers offer a grace period of up to 2.5 months into the next year to spend remaining FSA money, which gives you a small buffer. A few employers allow a carryover of up to $610 (for 2024) into the next year. Check your plan documents to see which option your employer uses. If your employer offers neither, you need to be more conservative with your estimate.

The safest approach is to contribute only the amount you're confident you'll spend. If you're uncertain, contribute less. The tax savings on $1,500 you definitely spend beats the tax savings on $2,500 where you might forfeit $500.

FSA versus HSA: which one makes more sense

If you have a high-deductible health plan (HDHP), you may be able to open a Health Savings Account (HSA) instead of or alongside an FSA. An HSA has major advantages: money rolls over year to year, you can invest it, and you can withdraw it tax-free for any reason after age 65 (though it's taxed as income if not used for medical expenses). An FSA has no rollover and no investment option.

You cannot have both an FSA and an HSA in the same year unless your FSA is a limited-purpose FSA that covers only dental and vision expenses. If you have access to an HSA, it usually offers better long-term value because your money is not forfeited. However, an FSA can still make sense if you have immediate, predictable medical expenses you know you'll incur this year.

Check your employer's plan documents or benefits summary to see whether you have access to an HSA, an FSA, or both. If you have both options, compare the contribution limits and your expected spending for the year.

What counts as an may be able to access FSA expense

FSA money can pay for copays, coinsurance, deductibles, and prescriptions. It covers dental work, vision care, and hearing aids. It covers over-the-counter medications (with a prescription from your doctor), medical equipment like crutches or blood pressure monitors, and some medical supplies. It does not cover health insurance premiums, cosmetic procedures, or general wellness items like vitamins or gym memberships.

The IRS maintains a detailed list of may be able to access expenses, and it's worth reviewing before you decide how much to contribute. Some items are may be able to access only under certain conditions — for example, sunscreen is not may be able to access, but prescription sunscreen is. If you're unsure whether something qualifies, ask your FSA administrator before you spend the money, because you cannot get reimbursed for ineligible expenses.

How to estimate your annual healthcare spending

Start by looking at what you actually spent on healthcare in the past year. Pull up your receipts, insurance statements, and pharmacy records. Add up copays, prescriptions, dental work, vision care, and any other out-of-pocket medical costs. That number is your baseline.

Then ask yourself whether next year will be similar. Are you planning any dental work, vision correction, or medical procedures? Will you need new glasses or contacts? Are you taking medications that will continue? Do you have a chronic condition that requires regular care? If the answer to most of these is no, and your baseline spending is low, an FSA may not be worth the risk.

If you have regular, predictable expenses, contribute an amount you're confident you'll spend. Many people contribute 80% to 90% of their estimated spending to leave a small margin for error. If your employer offers a grace period or carryover, you can be slightly more aggressive with your estimate.

The employer match and other employer contributions

Some employers contribute money to employee FSAs as part of the benefits package. This is assistance programs — you don't contribute it, but you can spend it on may be able to access healthcare expenses, and it's not taxed as income. If your employer offers this, it increases the value of the FSA significantly, because you're getting tax-assistance programs you didn't have to earn.

Check your benefits summary or ask your HR department whether your employer contributes to FSAs. If they do, that amount should factor into your decision. Even if you're uncertain about your own spending, an employer contribution makes an FSA more attractive because you're not risking your own money — you're just deciding whether to use the employer's contribution.

Frequently Asked Questions

What happens to FSA money I don't spend?

Under the standard rule, unspent FSA money is forfeited at the end of the plan year. Some employers offer a grace period (usually 2.5 months into the next year) to spend remaining funds, or allow a small carryover into the next year. Check your plan documents to see which applies to you.

Can I use my FSA for my spouse or children?

Yes. FSA money can pay for may be able to access medical expenses for you, your spouse, and your dependents, including adult children on your health plan. You don't have to be the one receiving the care — you just have to be the one paying for it with FSA funds.

Is an FSA worth it if I rarely go to the doctor?

Probably not. An FSA only saves you money on expenses you would incur anyway. If you rarely have medical costs, contributing to an FSA means you're likely to forfeit money at year-end. In that case, keeping the money in your paycheck is safer.

Can I change my FSA contribution during the year?

No, not unless you have a may have access to life event — marriage, birth of a child, loss of health coverage, or a significant change in your spouse's benefits. Outside of those events, your contribution is locked in for the plan year.

Should I choose an FSA if I have a high-deductible health plan?

If you can open an HSA instead, an HSA usually offers better value because money rolls over and is not forfeited. However, if your employer allows both, you might use a limited-purpose FSA for dental and vision expenses while using an HSA for medical expenses.