HSA vs. FSA: What's Different and Why It Matters

HSA and FSA are not the same, though both let you set aside pretax money for medical costs

A Health Savings Account (HSA) and a Flexible Spending Account (FSA) both reduce your taxable income when you contribute, but they work under different rules and suit different situations. An FSA is tied to your job and lets you set aside money each year for medical, dental, and vision expenses. An HSA is portable, stays with you even if you change jobs, and can grow like an investment account. The biggest difference: an HSA requires you to be enrolled in a high-deductible health plan, while an FSA works with any health insurance your employer offers.

Understanding which one you have access to—and which one fits your situation—matters because the rules about what you can spend the money on, how much you can contribute, and what happens to unused funds are different for each.

Key Takeaways

• An FSA is employer-sponsored and resets each year, while an HSA is portable, stays with you between jobs, and can accumulate balance year to year.
• An HSA requires enrollment in a high-deductible health plan; an FSA works with any employer health insurance.
• FSA contributions are typically limited to around $3,200 per year for individual coverage, while HSA limits are higher and vary by plan type.
• Unused FSA money is forfeited at the end of the year (with a small carryover option in some plans), but HSA money rolls over indefinitely and can be invested.
• Both accounts cover the same types of medical expenses, but an HSA offers more flexibility because the money is truly yours to keep.

How contribution limits differ

FSA contribution limits are set by your employer, but the IRS caps them at $3,200 per year for individual coverage (or $6,450 for family coverage) as of 2024. Your employer may set a lower limit. You choose your contribution amount during open enrollment each year, and that money is deducted from your paycheck before taxes.

HSA contribution limits are higher and depend on whether you have individual or family coverage under your high-deductible plan. For 2024, the limit is $4,150 for individual coverage or $8,300 for family coverage. You can contribute through payroll deductions, direct deposits, or by sending a check to the HSA custodian. Unlike an FSA, you can carry unused HSA money forward year after year, and it can be invested in mutual funds or other options depending on your account provider.

What happens to money you don't spend

This is where FSAs and HSAs diverge most sharply. FSA money that you don't spend by the end of the plan year is forfeited—you lose it. Some employers offer a "grace period" of up to 2.5 months into the next year to spend remaining FSA funds, or a carryover of up to $640 (as of 2024) into the next year. Check your plan documents to see which option your employer chose.

HSA money never expires. Whatever you don't spend stays in your account, grows tax-free, and can be used for medical expenses in any future year. If you leave your job, the HSA goes with you. You can even invest the balance in stocks, bonds, or mutual funds through most HSA custodians, turning it into a long-term savings tool for retirement healthcare costs.

Portability and what happens when you change jobs

An FSA is tied to your employer's plan. When you leave your job, you lose access to the FSA—any remaining balance is forfeited, even if your employer offered a carryover option. You cannot take the account with you or roll it into another account. If you move to a new job with an FSA, you start fresh with a new account and a new contribution election.

An HSA belongs to you, not your employer. You own the account and the money in it. When you change jobs, the HSA stays with you. You can keep the same HSA open, continue to use it for medical expenses, and even keep investing the balance. If your new employer offers an HSA, you can contribute to your existing account through payroll deductions at the new job. This portability makes an HSA a genuine long-term savings tool.

Which expenses both accounts cover

Both FSAs and HSAs cover the same IRS-approved medical expenses: doctor visits, prescriptions, dental work, vision care, mental health treatment, and medical equipment like crutches or hearing aids. Both also cover over-the-counter items like pain relievers and allergy medicine, though you may need to keep receipts as proof the expense was medical.

Neither account covers health insurance premiums (with a narrow exception for COBRA or long-term care insurance), cosmetic procedures, or gym memberships. The IRS publishes a detailed list of approved expenses on its website, and both your FSA and HSA provider should have a searchable database of common items.

When you can access the money

FSA funds are available as soon as you enroll, even if you have not yet contributed the full year's amount through payroll. You can use a debit card issued by your FSA plan to pay providers directly, or submit receipts for reimbursement. Some FSAs also let you request reimbursement for expenses you paid out of pocket.

HSA funds are available once your contribution hits the account. If you contribute through payroll, the money is deposited on the same schedule as your paychecks. You can use an HSA debit card to pay providers, request reimbursement, or simply pay out of pocket and reimburse yourself later—even years later, as long as you keep the original receipt.

Which account makes sense for your situation

Choose an FSA if you have predictable medical expenses each year and want to reduce your taxable income without worrying about investment options. FSAs are straightforward: contribute what you expect to spend, use the debit card, and move on. They work well for people with regular prescriptions, ongoing dental work, or frequent vision care.

Choose an HSA if you are enrolled in a high-deductible health plan and want a portable account that grows over time. HSAs suit people who can afford to pay medical expenses out of pocket and let the HSA balance accumulate, especially if they are healthy and do not expect to use much of it in the near term. An HSA also makes sense if you change jobs frequently or plan to retire early, because the account goes with you and can fund healthcare costs in retirement.

If your employer offers both, you can only use one in the same year. If you choose the HSA, you cannot contribute to an FSA. If you choose the FSA, you cannot open or contribute to an HSA.

Frequently Asked Questions

Can I use my FSA and HSA at the same time?

No. If you are enrolled in an HSA, you cannot contribute to an FSA in the same year. The IRS treats them as mutually exclusive. You must choose one or the other during open enrollment. Some employers offer a limited-purpose FSA that covers only dental and vision expenses alongside an HSA, but this is less common.

What if I have leftover FSA money and I'm changing jobs?

You lose it. FSA balances do not transfer between employers and do not roll over into an HSA. If your current employer offers a grace period or carryover, you have until the deadline to spend the remaining funds. After that, the money is forfeited.

Can I invest my HSA like a retirement account?

Yes, many HSA custodians let you invest the balance in mutual funds, index funds, or other securities once you reach a minimum balance (often $1,000 to $2,500). The growth is tax-free, and you can withdraw it tax-free for medical expenses at any age. After age 65, you can withdraw money for any reason, though non-medical withdrawals are taxed as income.

Do I have to use my FSA or HSA by a certain date?

FSA money must be spent by the end of the plan year, plus any grace period your employer offers. HSA money never expires—you can spend it this year or 20 years from now. This is one of the main reasons HSAs are considered more flexible.

What if my employer does not offer an HSA?

You can open an individual HSA on your own if you are enrolled in a high-deductible health plan through the individual market or a spouse's plan. You will contribute after-tax dollars and then deduct the contribution on your tax return, or you can set up a payroll deduction through some banks and HSA custodians. An individual HSA works the same way as an employer-sponsored one.