The core difference: who owns the money and how long you keep it

An HSA (Health Savings Account) is your personal savings account that you own permanently. Money you put in stays yours even after you leave your job, and you can spend it on healthcare costs anytime—now or decades from now. An FSA (Flexible Spending Account) is an employer-run account where you forfeit unspent money at the end of the year; it exists only while you work there.

This one difference cascades into everything else: HSAs let you invest the money and grow it tax-free, while FSAs are meant to be spent down annually. HSAs follow you between jobs. FSAs do not. If you change employers, your FSA money is gone (with rare exceptions for a grace period or carryover).

Both accounts let you set aside pre-tax dollars for medical expenses, which means you avoid federal income tax, Social Security tax, and Medicare tax on that money. But the permanence of an HSA makes it fundamentally different from an FSA, even though they look similar on a paycheck.

Key Takeaways

  • HSAs are yours to keep forever and can be invested; FSAs must be spent within the plan year or you lose the money.
  • You can only open an HSA if you have a high-deductible health plan (HDHP); FSAs work with any health plan your employer offers.
  • HSAs have higher annual contribution limits ($4,150 for individual coverage in 2024, varying by year) than FSAs (usually $3,300 per year, set by your employer).
  • After age 65, you can withdraw HSA money for any reason without penalty, though non-medical withdrawals are taxed as income.
  • FSAs let you claim a small carryover (up to $640 in 2024) or use a grace period (usually 2.5 months into the next year) to spend unused funds.

may be able to access: which account you can actually open

To open an HSA, you must be enrolled in a high-deductible health plan (HDHP). Your employer chooses whether to offer an HDHP, and you choose whether to enroll in it. The IRS sets the minimum deductible each year—for 2024, it is $1,600 for individual coverage and $3,200 for family coverage. If your plan's deductible is lower than that, you cannot open an HSA, even if you want to.

An FSA has no plan requirement. Your employer can offer an FSA alongside any health plan—a standard PPO, an HMO, a high-deductible plan, or even a plan with no deductible. If your employer offers an FSA, you can use it regardless of your health coverage.

This matters because many employers offer only one or the other, not both. If your employer offers only a standard health plan and an FSA, you cannot open an HSA. If your employer offers only an HDHP and no FSA, you can open an HSA but have no FSA option.

How much you can contribute each year

HSA contribution limits are set by the IRS and change annually. For 2024, you can contribute up to $4,150 if you have individual coverage, or $8,300 if you have family coverage. If you are 55 or older, you can add an extra $1,000 per year (called a catch-up contribution). These limits apply to all your HSAs combined—if you have two HSAs, your total contributions across both cannot exceed the limit.

FSA limits are also set by the IRS but are typically lower. For 2024, the limit is $3,300 per year for most employees, though some employers set lower limits. Unlike HSAs, FSA limits do not increase for age. Your employer may also set a lower cap than the IRS allows.

The higher HSA limit reflects the fact that you can carry money forward indefinitely. With an FSA, the IRS assumes you will spend the money within the year, so the limit is lower.

What happens to unspent money

Money in an HSA is yours permanently. If you do not spend it this year, it rolls into next year automatically. You can accumulate thousands of dollars over decades and use it whenever you need it. There is no deadline to spend HSA money, and no penalty for letting it sit.

FSA money works differently. At the end of the plan year, any balance you have not spent is forfeited—you lose it. This is called the "use-it-or-lose-it" rule. However, your employer can offer two safety valves: a carryover (allowing you to roll up to $640 into the next year) or a grace period (usually 2.5 months into the next year to spend the previous year's balance). Your employer chooses which option to offer, if any. Many employers offer neither.

Because of this rule, FSAs require you to predict your medical spending accurately. If you overestimate, you forfeit money. If you underestimate, you have to pay out of pocket.

Investment growth and long-term savings

HSAs can be invested in mutual funds, stocks, or other securities, just like a retirement account. Any growth is tax-free. If you invest $4,150 and it grows to $5,000, you owe no tax on that $850 gain. This makes HSAs powerful for people who do not need the money immediately and can let it grow over time.

FSAs cannot be invested. Your balance sits in a cash account earning no interest. This is another reason FSA limits are lower—the money is not expected to grow.

Over 20 or 30 years, an HSA can accumulate substantial wealth if you invest it and do not withdraw it. An FSA is a year-to-year spending account with no growth potential.

Portability: what happens when you change jobs

Your HSA belongs to you, not your employer. When you leave your job, you take the HSA with you. You can keep it open, continue to invest it, and use it to pay for medical expenses for the rest of your life. You can also roll it into a new HSA if your new employer offers one. The money is always yours.

An FSA is tied to your employer. When you leave, your FSA account closes. Any unspent balance is forfeited, even if you had a carryover or grace period. You cannot transfer it to a new employer's FSA or convert it to an HSA. The account simply ends.

This is a major advantage of HSAs for people who change jobs frequently or plan to retire early. An FSA is useful only while you are employed by that specific employer.

Withdrawal rules and penalties

You can withdraw money from an HSA anytime for any reason. If you use it for a may have access to medical expense (doctor visits, prescriptions, dental work, vision care, medical equipment, and many others), the withdrawal is tax-free and penalty-free. If you withdraw money for a non-medical reason before age 65, you owe income tax on the withdrawal plus a 20% penalty. After age 65, you can withdraw for any reason; non-medical withdrawals are taxed as income but have no penalty.

FSA withdrawals are simpler: you can only withdraw money for may have access to medical expenses during the plan year. You cannot withdraw for non-medical reasons at any age. If you try to withdraw for a non-medical reason, your employer will likely refuse or you will face tax consequences.

The HSA penalty for early non-medical withdrawal (20%) is the same as the Medicare penalty for early retirement account withdrawals, reflecting the account's long-term savings purpose.

Which account makes sense for your situation

Choose an HSA if your employer offers an HDHP and you can afford the higher deductible. HSAs are best for people who are generally healthy, do not expect major medical expenses this year, and want to build long-term healthcare savings. The tax advantages compound over time, and you keep the money forever.

Choose an FSA if your employer does not offer an HDHP, or if you have predictable medical expenses this year (ongoing prescriptions, planned procedures, regular therapy) that you know you will spend money on. FSAs are also useful if you want to set aside money for near-term costs without worrying about investment risk.

If your employer offers both, you can open an HSA and an FSA in the same year, though this is rare. The FSA lets you set aside money for predictable near-term costs, while the HSA builds long-term savings. However, you cannot use FSA money and then claim the same expense on your taxes, so coordinate carefully.

Frequently Asked Questions

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

You can have both if your employer offers both and you are enrolled in an HDHP. However, there is a catch: if you have an FSA, you cannot have a regular FSA and an HSA simultaneously—the IRS prohibits this combination. Some employers offer a limited-purpose FSA (for dental and vision only) alongside an HSA, which is allowed. Check with your employer's benefits team about what combination they support.

What counts as a may have access to medical expense?

may have access to expenses include doctor visits, hospital stays, prescriptions, dental work, vision care, hearing aids, medical equipment, and mental health treatment. Over-the-counter medications (like cold medicine or pain relievers) do not count unless you have a prescription. Cosmetic procedures, gym memberships, and vitamins do not count. The IRS publishes a full list, and your account provider can tell you whether a specific expense qualifies.

What happens to my FSA if I quit mid-year?

Your FSA account closes when you leave your job. You forfeit any unspent balance, even if you had contributed more money than you had used. Some employers allow a brief grace period (usually 30 to 60 days) to submit claims for expenses you incurred before you left, but the account itself is gone. This is why FSAs are risky if you think you might change jobs.

Can I use my HSA to pay for my spouse's medical expenses?

Yes. HSA money can be used for may have access to medical expenses of you, your spouse, and your dependents, regardless of whether they are covered under your health plan. You do not need to be on the same insurance plan. FSA rules are the same—you can use FSA money for your spouse's and dependents' medical expenses.

What happens to my HSA after I turn 65?

Your HSA continues to exist and grow. You can withdraw money for any reason without the 20% penalty, though non-medical withdrawals are taxed as income. Once you enroll in Medicare, you can no longer contribute to an HSA, but you can still withdraw from it. Many people use HSAs as a retirement account, letting the money grow until they need it for medical expenses in their 70s or 80s.