Can You Have Both an HSA and a Flex Spending Account at the Same Time

You cannot have both an HSA and a traditional flex spending account in the same year

The IRS treats an HSA and a Flexible Spending Account (FSA) as incompatible. If you enroll in a traditional FSA, you lose the right to contribute to an HSA that same calendar year. The rule exists because both accounts let you set aside pre-tax money for medical costs, and the IRS does not allow you to double-dip into tax-advantaged medical accounts simultaneously.

The restriction applies to the year you enroll, not just the months you are actively using the account. If you sign up for an FSA in January, you cannot open an HSA until the following January, even if you stop using the FSA in March. The same applies in reverse: if you have an HSA, you cannot enroll in a traditional FSA during open enrollment.

There is one narrow exception: a Limited-Purpose FSA (also called a restricted FSA) is designed to work alongside an HSA. This version covers only dental, vision, and hearing expenses, which means it does not conflict with HSA rules. If your employer offers a Limited-Purpose FSA, you can use it together with an HSA in the same year.

Key Takeaways

A traditional FSA and an HSA cannot both be active in the same calendar year under IRS rules.
The restriction applies to the entire year you enroll, even if you stop using one account partway through.
A Limited-Purpose FSA (covering only dental, vision, and hearing) can run alongside an HSA without triggering the conflict.
If you switch from an FSA to an HSA, you must wait until the next calendar year to open the HSA.
Unused FSA money does not roll over, so leaving an FSA means forfeiting whatever balance remains at year-end.

Why the IRS created this rule

Both accounts reduce your taxable income by letting you contribute pre-tax dollars. An HSA also grows tax-free and lets you withdraw money tax-free for medical expenses, making it more powerful than an FSA. If you could use both simultaneously, you could shelter far more income from taxes than the IRS intends.

The rule is part of a broader set of restrictions designed to prevent people from stacking tax advantages. The IRS assumes that if you have access to an HSA, you should use that instead of an FSA, because an HSA is the more flexible tool. An FSA is meant for people who cannot access an HSA—typically because they are on a non-high-deductible health plan.

What happens if you already have an FSA and want to switch to an HSA

You must wait until the next calendar year. If you are enrolled in an FSA on December 31, you cannot open an HSA on January 1 of the following year unless you first drop the FSA. Most employers allow FSA changes only during open enrollment or within 30 to 60 days of a may have access to life event (marriage, birth, loss of coverage, change in employment).

Before you leave an FSA, spend down your balance. FSA money does not roll over to the next year, and you forfeit whatever you do not use by December 31. Some employers offer a grace period (usually two and a half months into the new year) during which you can still claim expenses from the previous year, but this varies by plan. Check your FSA plan document or ask your benefits administrator before you make the switch.

If you have already contributed to an FSA for the year and then try to open an HSA, the HSA provider will reject your process. The IRS requires HSA trustees to verify that you are not enrolled in an FSA before accepting your contribution.

Limited-Purpose FSA: the workaround

A Limited-Purpose FSA covers only dental, vision, and hearing expenses. Because it does not overlap with HSA-may be able to access medical costs, the IRS allows you to hold both accounts in the same year. This is the only FSA structure that works alongside an HSA.

Not all employers offer a Limited-Purpose FSA. If yours does, you can contribute to both the Limited-Purpose FSA and the HSA during the same calendar year. The Limited-Purpose FSA has the same use-it-or-lose-it rule as a traditional FSA—unused money does not carry over—but it gives you a way to set aside pre-tax money for dental and vision costs while still building HSA savings for other medical expenses.

The contribution limits are separate. Your HSA has its own annual limit (set by the IRS each year), and your Limited-Purpose FSA has its own limit (also set by the IRS). You can max out both in the same year without triggering the conflict rule.

How to know which account makes sense for your situation

If you are on a high-deductible health plan (HDHP), you are may be able to access for an HSA and should generally choose it over an FSA. An HSA lets you carry money forward indefinitely, invest it, and withdraw it tax-free for medical costs. Once you turn 65, you can withdraw HSA money for any reason without penalty (though non-medical withdrawals are taxed as income). This makes an HSA a long-term savings tool, not just a year-to-year account.

If you are on a traditional health plan (PPO, HMO, or other non-HDHP), you are not may be able to access for an HSA. An FSA is your only option for pre-tax medical savings. In this case, the choice is straightforward: use the FSA if your employer offers it, and plan to spend down your balance each year.

If your employer offers both an HDHP (which qualifies you for an HSA) and a traditional plan with an FSA, choose the HDHP and HSA combination. The HSA's flexibility and long-term growth potential outweigh the FSA's year-to-year structure, even though the FSA lets you access money when ready without waiting for claims to process.

What to do if you enroll in the wrong account

If you enroll in an FSA and then realize you should have chosen an HSA, contact your benefits administrator when ready. Most employers allow you to cancel an FSA election within 30 days of enrollment if you have not yet used it. If you cancel within the allowed window, you may be able to open an HSA in the same year.

If you have already used FSA funds or the cancellation window has closed, you are locked into the FSA for the year. Plan to spend down your balance by December 31, and then switch to an HSA the following year. Do not leave money in the FSA at year-end—it will be forfeited.

Some employers offer a grace period or a carryover option (up to $610 in 2024, though this amount changes yearly). Check your plan documents to see if your FSA includes either feature. If it does, you may be able to carry a small amount forward, but this is rare and varies by employer.

Frequently Asked Questions

If I have an HSA, can I open an FSA later in the same year?

No. Once you have contributed to an HSA in a calendar year, you cannot enroll in a traditional FSA for that same year. You would have to wait until the next calendar year. A Limited-Purpose FSA is the only exception, since it does not conflict with HSA rules.

What if my employer switches from offering an FSA to offering an HDHP and HSA?

If your employer eliminates the FSA option and introduces an HDHP, that change counts as a may have access to life event. You can drop your FSA mid-year and enroll in the HDHP and HSA without waiting for open enrollment. Confirm this with your benefits administrator, and ask about the important date for making the switch.

Can I use my FSA to pay for dental and vision, then use my HSA for everything else?

Only if you have a Limited-Purpose FSA. A traditional FSA covers medical, dental, and vision expenses, so it conflicts with an HSA. If you have a traditional FSA, you cannot use an HSA at all that year. A Limited-Purpose FSA is specifically designed to cover only dental, vision, and hearing, leaving other medical expenses for the HSA.

Do I lose my FSA money if I switch to an HSA mid-year?

Yes, unless your plan includes a grace period or carryover option. FSA money does not roll over to the next year or transfer to an HSA. If you leave an FSA before December 31, any unused balance is forfeited. Spend down your FSA before you make the switch, or confirm that your plan allows a carryover.

If I have an HSA from one job and move to a new job with an FSA, what happens?

You cannot contribute to the new FSA in the same calendar year you contributed to the HSA at your previous job. You can keep your existing HSA open and continue to use it, but you cannot enroll in the new employer's FSA until the next calendar year. If the new employer offers a Limited-Purpose FSA instead, you can enroll in that while keeping your HSA active.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.