Both accounts let you pay medical costs with pre-tax dollars, but their rules are very different.
Key differences
An HSA requires a high-deductible plan, is owned by you, rolls over indefinitely and can be invested. A health FSA is available with most employer plans, is generally use-it-or-lose-it with a limited carryover or grace period and belongs to the employer plan.
Limits
For 2026 the health FSA limit is $3,400, while HSA limits are $4,400 for self-only and $8,750 for family coverage. A limited-purpose FSA can be paired with an HSA for dental and vision.
How to choose
If you are eligible for an HSA, it is usually better for long-term savings. Choose an FSA when your plan is not HDHP-qualified and you have predictable expenses. Never elect more into an FSA than you are confident you will spend.
Try the numbers
Use our FSA Savings Calculator to see this in practice. With its default example (FSA election: $2,500; Expected eligible spending: $2,100; Marginal tax rate: 22%), it shows tax savings: $623. Adjust the inputs to match your situation.
Key takeaways
- HSAs roll over and are portable; FSAs are use-it-or-lose-it.
- You generally cannot contribute to a regular FSA and an HSA together.
- Only fund an FSA with amounts you will spend.
This article is for general education and is not personalized financial, tax or legal advice. Rules and limits change; confirm current figures with official sources such as IRS.gov, SSA.gov and StudentAid.gov, or consult a qualified professional. © 2026 FinanzCalc.