The core promise: no recovery, no fee
A contingency fee means the attorney's fee is contingent — dependent — on actually winning or settling the case. If there's no recovery at all, the client generally owes no attorney fee, regardless of how much work went into the case.
What the agreement is legally required to say
Hawaii Rule of Professional Conduct 1.5(d) requires a contingent fee agreement to be in writing, signed by the client, and to clearly state the method by which the fee will be determined — including the percentage that applies at settlement, trial, or appeal, what litigation expenses will be deducted, and whether those expenses are deducted before or after the fee itself is calculated.
No cap, in any type of case
Hawaii places no statutory cap on the contingency fee percentage anywhere — not for an ordinary car accident case, and not for medical malpractice either. The rate is negotiated privately between attorney and client, subject only to Rule 1.5's general reasonableness requirement.
A real legislative history of trying, and failing, to add one
This wasn't for lack of effort. Between 2008 and 2010, Hawaii lawmakers introduced several bills as part of a broader "Hawaii Non-Economic Damages Cap Act" package aimed at addressing medical malpractice insurance costs. Alongside a cap on non-economic damages, these bills proposed a tiered statutory limit on contingency fees specifically for medical tort cases. The fee-cap provisions were never enacted into law, even as the damages cap itself (HRS § 663-8.7) ultimately passed on its own track.
Two separate legal questions, worth keeping distinct
It's worth not conflating these: Hawaii's existing damages cap limits what a plaintiff can recover for pain and suffering. It says nothing about what percentage of that recovery an attorney may charge as a fee — that question remains entirely unregulated by statute in Hawaii, governed only by the general reasonableness standard.