Tools · Open enrollment

HSA vs FSA calculator

HDHP + HSA vs copay plan + general health FSA. Caps from Rev. Proc. 2026-24 (2027) and 2025-19 / 2025-32 (2026). Read the open-enrollment guide first. Quotes from your SBC, not a benefits-fair poster.

Quick answer: This calculator compares a high-deductible plan plus an HSA with a copay plan plus a general health FSA for the year you pick. Caps, HDHP tests, and the FSA limit are the IRS figures already printed on the page. Premiums and spending are yours.

Plan year Coverage Age 55 or older this year Enrolled in Medicare Expected billed charges this year Light-year billed Bad-year billed Federal + state + FICA combined %

Default 22% federal + 7.65% FICA. Add your state. Premiums are modeled pretax (section 125).

HDHP + HSA

Employee premium (annual) Deductible Coinsurance % after deductible In-network OOP max (not premiums) Employer HSA seed Your HSA contribution Limited-purpose FSA (dental/vision)

Copay / PPO + health FSA

Employee premium (annual) Deductible Coinsurance % after deductible In-network OOP max Health FSA election FSA leftover

HSA cap

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Net cost = employee premium + patient share − employer HSA − tax saved on employee HSA (and on FSA dollars that actually pay claims). Unused FSA is a cost unless you toggle carryover. HSA leftover is an asset, not a cost. 2027 HSA / HDHP: Rev. Proc. 2026-24. 2026 health FSA $3,400 / $680 carryover: Rev. Proc. 2025-32. Paid sequence: HSA playbook. Triple-tax mechanics: primer.

What this means for you

What this means for you: the result is employee premium plus what you pay for care, minus employer HSA money and the tax savings the model allows. Unused FSA is a cost unless you turn carryover on. HSA money you do not spend stays an asset in this model. Confirm the summary of benefits.

How to use this calculator

Open the HSA vs FSA calculator and keep the sample numbers or replace them with your own. The result updates as you type.
Read the headline figure first, then the breakdown or chart under it.
Use Copy share link if you want those inputs in the URL. The page is an educational estimate, not a filing, approval, or recommendation.

FAQ

Which limits does the HSA calculator use?

The year toggle uses the 2026 and 2027 HSA and HDHP figures, and the 2026 FSA figure, already written on the page. This review did not change them.

What happens to unused FSA money?

The page treats unused FSA as a cost unless you toggle carryover. That matches a use-it-or-lose-it health FSA, not an HSA.

Is the lowest-cost plan always the HDHP?

No. A year with high care can erase the premium savings. The page runs more than one spending year.

Educational, not financial advice. Page updated October 24, 2026 — no tax, limit, or rate figure was changed in this review.