HSA vs FSA Calculator
Both let you pay for medical expenses with pre-tax dollars, but the rules differ sharply: the HSA needs a high-deductible health plan and its dollars never expire, while the FSA has use-it-or-lose-it forfeiture risk. Compare estimated 2026 tax savings side by side. US-specific — figures are IRS limits for 2026.
Estimated tax savings
The HSA's triple tax advantage: deductible going in, tax-free growth, tax-free withdrawals for medical expenses. Unlike the FSA, HSA dollars never expire — unspent money can be invested and kept growing for retirement.
FSA use-it-or-lose-it check
✓ No forfeiture risk at these numbers — unspent dollars up to $680 carry over to next year.
Common questions
What is the triple tax advantage of an HSA?
Contributions are tax-deductible (or pre-tax through payroll), the money grows tax-free, and withdrawals for qualified medical expenses are tax-free too. No other common account hits all three — that is why financial planners love HSAs as a retirement vehicle, not just a medical account.
Can I have an HSA and an FSA at the same time?
Generally no — a general-purpose health FSA disqualifies you from contributing to an HSA. The exception is a limited-purpose FSA (dental and vision only), which can pair with an HSA. This calculator treats them as alternatives for that reason.
What happens to FSA money I don't spend?
Plans may let you carry over a limited amount ($680 for 2026 under IRS rules) or give a short grace period — otherwise unspent dollars are forfeited. HSA dollars, by contrast, are yours forever and can be invested.