Both accounts let you pay for medical costs with pre-tax money, which is why they get compared so often. They work very differently, though. An HSA is a savings account you own, available only if you are covered by a qualifying high-deductible health plan (HDHP). A health FSA is an employer benefit with a lower limit and stricter rules about unused money.
This page compares the two side by side using the 2026 IRS figures, explains when you can have both, and sets out the questions that decide which suits you. It is general information, not advice for your situation. The limit details are in our HSA contribution limits guide and FSA limits guide.
| Health FSA | HSA | |
|---|---|---|
| 2026 contribution limit | $3,400 | $4,400 self-only; $8,750 family |
| Who can have one | Employees whose employer offers an FSA; self-employed people are not eligible | People covered by a qualifying HDHP, with no other disqualifying coverage, not enrolled in Medicare and not claimed as a dependent |
| Who owns it | Set up through your employer's plan | You; it stays with you if you change employers |
| Unused money at year end | Generally lost; plan may allow a $680 carryover or a grace period of up to 2 1/2 months, not both | Generally carried over to the next year |
| Tax on contributions | Salary reduction under the employer plan | Deductible, even if you do not itemize |
| Tax on spending | Reimbursements for eligible medical expenses are tax free | Distributions may be tax free if used for qualified medical expenses |
| Access to money | Full elected amount available any time in the coverage period | You can take a distribution at any time, but only amounts used exclusively for qualified medical expenses are tax free |
Sources: IRS Publication 969 (2025), Publication 15-B (2026), Revenue Procedure 2025-19 (HSA) and Revenue Procedure 2025-32 (FSA).
For 2026 the HSA limit is $4,400 for self-only coverage and $8,750 for family coverage. A qualifying HDHP has an annual deductible of at least $1,700 for self-only coverage or $3,400 for family coverage, and annual out-of-pocket expenses (deductibles, co-payments and other amounts, but not premiums) that do not exceed $8,500 for self-only coverage or $17,000 for family coverage (Revenue Procedure 2025-19).
To contribute you must be covered under an HDHP on the first day of the month, not be enrolled in Medicare, and not be claimable as a dependent on someone else's return, and you must have no other health coverage except what is permitted. You can claim a deduction for contributions you or someone other than your employer make, even if you do not itemize. The contributions remain in the account until you use them, the earnings are tax free, and the account is portable.
The deadline for 2025 contributions was April 15, 2026 (IRS Publication 969); the equivalent deadline for 2026 contributions follows the same pattern, so check IRS Publication 969 when it is updated. For calendar year 2027 the IRS has already set the HSA limits at $4,500 for self-only coverage and $9,000 for family coverage (Revenue Procedure 2026-24); the 2026 limits above apply to 2026 contributions.
The 2026 health FSA limit is $3,400. FSAs are employer-established plans, so you can only join one your employer offers, and self-employed people are not eligible. You can change or revoke your election only if the law and your plan allow it. You must be able to receive the full amount you elected at any time during the coverage period, regardless of how much you have actually contributed so far. See our FSA limits guide for the dependent care FSA, carryover and grace period rules.
Generally not with a general-purpose health FSA. An employee covered by an HDHP and a health FSA or HRA that pays or reimburses qualified medical expenses cannot generally make contributions to an HSA. An employee can still contribute to an HSA while covered under an HDHP and certain other arrangements, including a limited-purpose FSA that only pays for specific kinds of expenses. If your employer offers both a general-purpose and a limited-purpose FSA, picking the right one matters.
Neither account lets you deduct, as an itemized medical expense, amounts that the account already reimbursed or paid tax free.
None of this is a recommendation for your circumstances. A benefits adviser or tax professional can look at your plan options and your finances together.
Primary documents for this comparison: IRS Publication 969, Revenue Procedure 2025-19 (HSA amounts) and IRS Publication 15-B (FSA limits).