Most states that regulate the fee set a number
Illinois caps medical malpractice attorney fees at a flat 33⅓%. Florida's constitutional cap is tiered by dollar amount. Both approaches give an attorney (and a court) a specific percentage to check against.
Iowa sets a process instead of a number
Iowa Code § 147.138 doesn't write any percentage into the statute at all. Instead, it requires the court to affirmatively determine the reasonableness of any contingent fee arrangement in a personal injury or wrongful death action against a licensed health care provider or hospital — a mandatory, automatic judicial check built into every such case, not something that only happens when a client objects.
A specific percentage was considered, and didn't become law
Iowa's legislature has considered an actual percentage cap in this space before — one proposal would have capped medical malpractice contingency fees at 35%. That specific cap did not become Iowa's governing rule; the mandatory court-review requirement under § 147.138 remains the operative structure instead.
Real discretion, exercised case by case
Without a fixed ceiling, a court reviewing a fee under § 147.138 has genuine discretion to find a specific proposed rate unreasonable on the facts of that case, even where the same rate might be unremarkable in an ordinary personal injury matter. That flexibility cuts both ways: it can accommodate an unusually complex or risky case, but it also means the outcome isn't guaranteed by a bright-line number the way a flat cap would provide.
A distinctive structural choice nationally
Building mandatory judicial review into the statute, rather than a specific numeric ceiling, is a less common approach among states that regulate medical malpractice attorney fees at all — most states that act in this space choose a number instead of a process.