Standard Tier Module
HSA / FSA Contribution Optimizer
HSA-first contribution strategy with exact IRS-limit caps and FSA forfeiture-risk math, in your browser.
See it run - a worked example, 100% in this browser tab
The problem
Employees and benefits advisors routinely overfund a health FSA into forfeiture or unknowingly disqualify HSA eligibility by holding a general-purpose FSA, leaving real pre-tax dollars on the table.
The local-first solution
This plugin recommends an HSA-first contribution path deterministically in the browser, capping each account at its cited IRS limit and flagging the eligibility interaction, with exact arithmetic and no personal financial data sent to any server.
What it does
HSA contribution capped at the IRC 223(b) tier limit plus the $1,000 age-55 catch-up
Estimated tax savings = contribution x your entered marginal rate
Health-FSA path capped at the IRC 125(i) limit with use-it-or-lose-it forfeiture risk above expected expenses
HSA-first steering with FSA flagged only as a limited-purpose complement
General-purpose-FSA HSA-eligibility disqualification flag (IRC 223(c)(1)(A)(ii); Rev. Rul. 2004-45)
The exact HSA, catch-up, FSA, and carryover limits it actually used surfaced for the plan year
Honest scope
The cap arithmetic, the tax-savings multiply, and the forfeiture-risk subtraction are exact; the HSA/FSA limits, catch-up, and carryover cap are year-indexed inputs you confirm against the IRS Rev. Proc. or Notice. The marginal rate is your input applied as a flat multiplier - an estimate, not a return. Not modeled: mid-year proration/last-month rule, employer HSA contributions, the actual bracket/FICA/state computation, and FSA grace-period plans. This is not tax, legal, or financial advice.
Authorities cited
- IRC 223(b) - Maximum annual HSA contribution by coverage tier (self-only / family); contributions are above-the-line deductible.
- IRC 223(b)(3) - Additional $1,000 "catch-up" HSA contribution for an account beneficiary who has attained age 55 (statutory, not inflation-indexed).
- IRC 223(c)(1)(A)(ii) - An individual covered by disqualifying "other coverage" (including a general-purpose health FSA) is not an eligible individual and may not contribute to an HSA.
- IRS Rev. Proc. (annual) - The inflation-adjusted HSA limits: Rev. Proc. 2023-23 (2024: $4,150 self / $8,300 family) and Rev. Proc. 2024-25 (2025: $4,300 self / $8,550 family). Confirm the Rev. Proc. for your tax year.
- IRC 125(i) - The indexed limit on health-FSA salary-reduction contributions; Rev. Proc. 2023-34 (2024: $3,200) and Rev. Proc. 2024-40 (2025: $3,300).
- IRS Notice 2013-71 / Notice 2020-33 - The health-FSA carryover option and its indexed cap (the maximum unused amount that may carry into the next plan year): $640 for 2024, $660 for 2025. A plan may instead offer a 2.5-month grace period (not both).
- Rev. Rul. 2004-45 - A LIMITED-PURPOSE FSA (dental/vision) or post-deductible FSA does NOT disqualify HSA eligibility, whereas a general-purpose health FSA does; a general-purpose FSA carryover can taint HSA eligibility for the following year.
- IRC 125(d) / Prop. Treas. Reg. 1.125-1 - Health-FSA "use-it-or-lose-it": unused amounts above any permitted carryover or grace period are forfeited at plan-year end.
Optimize your contribution
Compute the HSA-first path and FSA risk in your browser, then route the result to a Sandbox workspace, a Worklog case, or a Gate client portal. Nothing is uploaded to anyone's cloud.