HSA and FSA are separate accounts that let you set aside pre-tax money for medical costs, but they have different rules about what you can save, how long you can keep the money, and who can open one

Both accounts reduce your taxable income by letting you pay for medical expenses before taxes are taken out of your paycheck. The money you put in is not subject to federal income tax or Social Security tax. But they are not interchangeable. An HSA (Health Savings Account) is a long-term savings tool tied to a high-deductible health plan, while an FSA (Flexible Spending Account) is a shorter-term benefit tied to your employer and resets each year. Understanding which one you have access to, and how each one works, determines how much you can save and what happens to money you do not spend.

The most important difference is permanence. HSA money is yours to keep forever, even after you leave your job. FSA money belongs to your employer's plan and disappears when you do. This single fact shapes every other rule about how much you can contribute, what you can do with unused balances, and whether it makes sense to use one account or the other.

Key Takeaways

  • HSAs let you save money year after year and carry unused balances forward indefinitely, while FSAs typically reset to zero each January and you lose unspent money.
  • You can only open an HSA if your health insurance is a high-deductible plan; FSAs are offered by employers regardless of your plan type.
  • HSA contribution limits are set by the IRS and change yearly; FSA limits are also set by the IRS but are usually lower, and your employer decides whether to offer one.
  • Both accounts cover the same types of medical expenses: copays, deductibles, prescriptions, dental, vision, and many over-the-counter items, but the IRS rules on what counts are identical for both.
  • If you leave your job, you keep your HSA money forever, but FSA money stays with your employer's plan and you lose access to it once you separate.

How HSA and FSA contributions work

Both accounts are funded through payroll deduction, meaning money comes out of your paycheck before taxes are calculated. Your employer may also contribute to an HSA (many do), but employers do not contribute to FSAs—only you do. For 2024, the IRS allows you to contribute up to $4,150 for individual coverage or $8,300 for family coverage to an HSA. FSA limits are lower: up to $3,200 per year for most employers, though some employers set their own lower limits within IRS rules.

The key difference is what happens to money you do not spend. With an HSA, unused money rolls over to the next year automatically. You can let it sit and grow for decades if you want. With an FSA, most employers operate under a "use-it-or-lose-it" rule: money left in the account at the end of the year is forfeited. Some employers offer a grace period (usually 2.5 months into the next year) or a carryover of up to $640, but this varies by employer and is not may provide. You should check your employer's benefits guide or ask your HR department what rule applies to your FSA.

may be able to access: who can open each account

You can only open an HSA if you are enrolled in a high-deductible health plan (HDHP). The IRS defines an HDHP as a plan with a deductible of at least $1,600 for individual coverage or $3,200 for family coverage in 2024. If your employer offers a standard PPO or HMO plan with a lower deductible, you cannot open an HSA, even if you want to. You also cannot be claimed as a dependent on someone else's tax return, and you cannot be enrolled in Medicare.

FSAs have no such restrictions. Your employer simply decides whether to offer one as part of your benefits package. You can have an FSA whether your health plan is high-deductible, standard, or anything else. However, you cannot have both an HSA and an FSA in the same year—the IRS prohibits this because both accounts are designed to reduce your tax burden on medical spending, and stacking them would be too generous. If you are enrolled in a high-deductible plan and your employer offers both, you must choose one at open enrollment.

What expenses both accounts cover

The IRS maintains a single list of may have access to medical expenses, and both HSAs and FSAs cover the same items. This includes copays and coinsurance, deductibles, prescription medications, dental work (fillings, crowns, orthodontics), vision care (exams, glasses, contacts), hearing aids, mental health counseling, and physical therapy. Over-the-counter items like pain relievers, allergy medicine, and antacids are covered if you have a prescription or a doctor's note. Menstrual products became covered in 2023.

Items that do not count include cosmetic procedures, gym memberships, vitamins without a medical condition, and most over-the-counter items without a prescription. If you are unsure whether a specific expense qualifies, your account administrator (the company that manages your HSA or FSA) can tell you before you spend the money. Many providers have online tools or customer service lines that can answer this question in minutes.

What happens to your money when you change jobs

If you leave your job or change health plans, your HSA stays with you. The money is yours permanently. You can take the account to a new HSA provider, keep it where it is, or roll it into another HSA. You can continue to use it to pay for may have access to medical expenses for the rest of your life, even after you retire or enroll in Medicare (though you cannot make new contributions once you are on Medicare). This portability is one of the biggest advantages of an HSA.

FSA money does not follow you. When you leave your job, you lose access to the FSA account and any money remaining in it. Some employers allow you to continue using the FSA for a limited time under COBRA (Consolidated Omnibus Budget Reconciliation Act), but you have to pay the full premium yourself, and the money still resets at the end of the plan year. This is one of the biggest practical differences between the two accounts and a major reason why HSAs are often considered better for long-term planning.

HSA as a retirement savings tool

Because HSA money rolls over indefinitely and you can invest it (most HSA providers offer investment options), an HSA can function as a retirement account. You can let the money grow tax-free for years, then use it to pay for medical expenses in retirement. After age 65, you can withdraw HSA money for any reason without penalty, though non-medical withdrawals are subject to income tax (just like a traditional IRA). Many people treat their HSA as a supplemental retirement fund, paying for current medical expenses out of pocket and letting the account balance grow.

An FSA cannot be used this way. It is designed as a year-to-year spending account, not a savings vehicle. Once the plan year ends, the money is gone. This makes FSAs useful for people who know they will have predictable medical expenses each year, but not for long-term planning. If you have an FSA, you should think of it as a tool to reduce taxes on expenses you will definitely incur within the next 12 months.

How to choose or use what you have

If your employer offers both an HSA and an FSA, you cannot have both at the same time. If you have a high-deductible plan and expect significant medical expenses, an HSA is usually the better choice because you keep the money and can let it grow. If you have a standard health plan or prefer not to manage investments, an FSA lets you save on taxes for predictable costs like copays and prescriptions, knowing you will spend the money within the year.

If you already have an FSA, treat it as a spending account: estimate your medical costs for the year, contribute that amount, and plan to use it by December 31 (or your employer's deadline). If you have an HSA, contribute what you can afford and think of it as a long-term medical savings account. Many people use their HSA to pay for current medical expenses out of pocket and let the HSA balance grow, treating it as a supplemental retirement fund. The choice depends on your health plan type, your expected medical costs, and whether you want to save money long-term or just reduce taxes on near-term expenses.

Frequently Asked Questions

Can I have both an HSA and FSA at the same time?

No. The IRS prohibits holding both accounts in the same year. If you are enrolled in a high-deductible plan and your employer offers both, you must choose one at open enrollment. If you switch from an FSA to an HSA, you must wait until the next plan year to open the HSA.

What happens to my FSA money if I do not spend it by the end of the year?

Most employers operate under a use-it-or-lose-it rule, meaning unspent FSA money is forfeited. Some employers offer a grace period (usually 2.5 months into the next year) or allow you to carry over up to $640, but this depends on your employer's plan. Check your benefits guide or ask your HR department what your plan allows.

Can I withdraw HSA money for non-medical expenses?

Yes, but with a penalty. Before age 65, withdrawing HSA money for non-medical expenses triggers a 20% penalty plus income tax on the amount withdrawn. After age 65, you can withdraw money for any reason without penalty, though non-medical withdrawals are taxed as income.

Do I have to spend my HSA money on medical expenses in the same year I contribute it?

No. HSA money can be spent in any year, even decades later. You can contribute in 2024 and use the money in 2034. This is one of the main advantages of an HSA over an FSA and makes it useful as a long-term savings tool.

What if my employer does not offer an HSA or FSA?

If you have a high-deductible plan, you can open an HSA on your own through a bank or financial institution, even if your employer does not offer one. You would contribute after-tax money and then deduct the contributions on your tax return. FSAs are only available through employers, so if your employer does not offer one, you cannot open an FSA independently.