An FSA saves money only if you will actually spend the money on may have access to expenses

A Flexible Spending Account is worth it if you have predictable medical or dependent care costs you know you will pay out of pocket this year. The account lets you set aside pre-tax money — meaning you avoid federal income tax, Social Security tax, and Medicare tax on that amount. For someone in the 22% federal tax bracket, setting aside $2,500 means you save roughly $550 in taxes. That is real money back in your pocket.

But an FSA is not worth it if you are not certain you will spend what you contribute. Money left in an FSA at the end of the plan year is forfeited — you cannot roll it over to next year or take it out. This "use it or lose it" rule is the single biggest reason people regret opening an FSA. You have to be honest about what you will actually spend, not what you might spend or what would be nice to spend.

The math only works if the tax savings outweigh the risk that you will not use all the money. If you are unsure whether you will hit your target, a lower contribution is safer than a higher one.

Key Takeaways

  • An FSA saves you money through taxes only if you spend the full amount you contribute before the plan year ends.
  • Money you do not spend is forfeited — there is no rollover, no refund, and no way to get it back.
  • The tax savings are real but modest: roughly 20% to 37% of what you contribute, depending on your tax bracket.
  • An FSA makes the most sense if you have steady, predictable medical or dependent care costs you pay for every year.
  • If your expenses vary widely or you are not sure what you will spend, contributing less or not opening an FSA at all may be the safer choice.

How much you actually save in taxes

The tax savings from an FSA depend on your tax bracket. If you contribute $2,500 to a healthcare FSA, you avoid paying federal income tax on that $2,500. You also avoid Social Security tax (6.2%) and Medicare tax (1.45%) on that amount. For someone in the 22% federal bracket, the total tax savings is roughly 29.65% of the contribution — about $741 on $2,500.

Someone in the 12% federal bracket saves about 19.65% — roughly $491 on $2,500. Someone in the 32% bracket saves about 39.65% — roughly $991 on $2,500. The higher your tax bracket, the more you save.

That savings is only real if you spend the money. If you contribute $2,500 and spend only $1,800, you lose the tax benefit on the $700 you did not use, plus you lose the $700 itself. You end up worse off than if you had not opened the account.

When an FSA is worth the risk

An FSA makes sense if you have medical or dependent care costs you know are coming and you know roughly how much they will be. Examples include ongoing prescriptions, regular therapy or counseling, dental work you have already scheduled, vision care, or childcare while you work.

If you have a child in daycare, you know the cost per month and can calculate the annual total. If you take regular medications, you know the copay or coinsurance per prescription and how often you refill. If you wear glasses or contacts and get new ones every year or two, you can estimate that cost. These are the situations where an FSA works well — you have a clear number to aim for.

An FSA also makes sense if your employer offers a grace period or a carryover option. Some plans let you carry over up to $570 (the 2024 limit) to the next year, or they give you a 2.5-month grace period after the plan year ends to spend remaining money. Check your plan documents to see if either applies to you. If your plan has one of these features, the risk of losing money drops significantly.

When an FSA is not worth it

An FSA is risky if your medical or dependent care costs are unpredictable. If you do not know whether you will need a major dental procedure, or if your child's school schedule might change, or if you might change jobs and lose access to childcare, you cannot safely estimate what you will spend.

An FSA is also not worth it if you are already in a low tax bracket or if you have very small medical expenses. If you only spend $300 a year on out-of-pocket medical costs, the tax savings is roughly $90. That is not enough to justify the risk of losing money if your expenses drop.

If you have a high-deductible health plan paired with a Health Savings Account (HSA), an FSA may not be allowed, and an HSA is usually the better choice anyway because HSA money rolls over year to year and is not forfeited.

The forfeiture rule and how to avoid it

The "use it or lose it" rule is set by federal law. Any money left in your FSA at the end of the plan year is forfeited to your employer. There are no exceptions, no refunds, and no way to recover it. This is the biggest reason people regret opening an FSA.

To avoid forfeiture, contribute only what you are confident you will spend. If you are unsure, start low — you can usually increase your contribution next year if you realize you spent more than you expected. If your plan allows it, use up remaining money during the grace period by scheduling appointments or buying over-the-counter items before the deadline.

Keep receipts and track your spending throughout the year so you know how much you have left to spend. Many FSA providers offer a mobile app or online portal where you can see your balance in real time. Use that tool to stay on track.

FSA versus other ways to save on medical costs

An FSA is one tool, but it is not the only one. If you have a high-deductible health plan, a Health Savings Account (HSA) is usually better because the money rolls over and is never forfeited. You can invest HSA money and let it grow, and you can use it for medical costs in retirement.

If you do not have predictable expenses or you are worried about forfeiture, you might simply pay medical costs out of pocket and claim the medical expense deduction on your taxes if you itemize. This does not save as much as an FSA, but there is no risk of losing money.

If you have dependent care costs, a dependent care FSA works the same way as a healthcare FSA — you set aside pre-tax money and forfeit what you do not spend. The tax savings is the same, but the forfeiture risk is also the same. Only open one if you are certain about your childcare costs for the year.

Questions to ask yourself before opening an FSA

Before you enroll, write down your medical and dependent care costs from the past two years. Add them up month by month. Do you see a clear pattern? Are the costs roughly the same every year, or do they vary widely?

Next, think about what might change this year. Are you planning any procedures? Will your child's school schedule change? Might you change jobs? If there is a real chance your costs will drop, contribute less than you think you might spend.

Finally, check your plan documents. Does your employer's FSA have a grace period or carryover option? If so, the risk is lower and you can contribute a bit more confidently. If not, be conservative.

Frequently Asked Questions

Can I get my FSA money back if I do not spend it?

No. Money left in your FSA at the end of the plan year is forfeited. There is no refund, no rollover to next year, and no exception. Some plans offer a grace period (usually 2.5 months after the year ends) to spend remaining money, or they allow you to carry over up to $570 to the next year. Check your plan documents to see if either applies to you.

What counts as a may have access to FSA expense?

For a healthcare FSA, may have access to expenses include copays, coinsurance, deductibles, prescriptions, dental work, vision care, therapy, and many over-the-counter items like pain relievers and first aid supplies. For a dependent care FSA, may have access to expenses are childcare, preschool, and adult daycare while you work. The IRS publishes a full list of may have access to expenses on its website.

Should I open an FSA if I have an HSA?

If you have a high-deductible health plan, you can use an HSA but not a healthcare FSA at the same time. An HSA is usually better because the money rolls over year to year and is never forfeited. You can invest it and use it in retirement. A dependent care FSA can be used alongside an HSA if you have childcare costs.

What if my expenses are lower than I expected?

If you realize mid-year that you will not spend all the money you contributed, you cannot get a refund or change your contribution until the next open enrollment period. Your only option is to spend the remaining money on may have access to expenses before the plan year ends (or during the grace period if your plan has one). This is why starting with a lower contribution is safer if you are unsure.

Is the tax savings worth the risk of losing money?

It depends on how confident you are about your spending. If you are very sure you will spend the money, the tax savings of 20% to 37% is worth it. If you are unsure, the risk of losing money outweighs the tax benefit. When in doubt, contribute less or do not open an FSA at all.