No percentage cap
South Dakota imposes no statutory percentage cap on contingency fees in personal injury or medical malpractice cases. The governing standard is Rule 1.5 of the South Dakota Rules of Professional Conduct, which prohibits an unreasonable fee rather than fixing a specific figure.
Even flat fees face the same scrutiny
South Dakota ethics guidance has addressed this directly for flat-fee arrangements: State Bar Ethics Opinion 2000-5a confirms that a fixed or flat fee must still be subject to a separate reasonableness review under Rule 1.5's eight factors — the same analysis a contingency fee receives. Agreeing to any particular fee structure doesn't, by itself, make the resulting amount reasonable.
What reasonableness actually weighs
Rule 1.5 points to the usual factors: the time and labor required, the novelty and difficulty of the questions involved, the skill needed to perform the work properly, the fee customarily charged for similar legal services in the locality, the amount involved, and whether the fee is fixed or contingent. One-third of the recovery is a commonly used figure in South Dakota personal injury practice, though it isn't a fixed statutory rate.