The 2026 HSA rules the ranking calculators get wrong.
Short, plain-language explainers on the three things that actually move your HSA number: the Medicare 6-month lookback, the California & New Jersey state tax, and what the 2026 law changed. Then run your own numbers in the calculator.
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The Medicare 6-month lookback that erases HSA contributions
Enrolling in Medicare Part A after 65 backdates up to six months, and claiming Social Security at 65 forces Part A you can't refuse. Here's why your real stop-contributing date is your application month minus six — and how earlier contributions become excise-taxed excess.
HSA state tax: only California and New Jersey, and why it matters
The federal "triple-tax-free" line is wrong for two states. CA and NJ don't allow the deduction and tax your in-account earnings every year — so the compound-tax-free premise weakens. What's real, what's obsolete (TN and NH), and how much drag it adds.
What the 2026 OBBBA law actually changed for HSAs
Three HSA changes are enacted: bronze/catastrophic Exchange plans and Direct Primary Care are now compatible, and the telehealth safe harbor is permanent. Just as important — the widely-rumored provisions that didn't pass, so you don't plan around them.
The 2026 HSA Triple-Tax Optimizer computes your real contribution ceiling after Medicare proration and the catch-up rules, the triple-tax dollar value netted of CA/NJ state tax, and a stealth-retirement projection. It runs entirely in your browser — nothing you enter leaves your device.
These guides are educational and not tax, legal, or medical advice. See our disclaimer.