Cal. BPC § 6146

(a) An attorney shall not contract for or collect a contingency fee for representing any person seeking damages in connection with an action for injury or damage against a health care provider based upon such person’s alleged professional negligence in excess of the following limits:

(1) Twenty-five percent of the dollar amount recovered if the recovery is pursuant to settlement agreement and release of all claims executed by all parties thereto prior to a civil complaint or demand for arbitration being filed.

(2) Thirty-three percent of the dollar amount recovered if the recovery is pursuant to settlement, arbitration, or judgment after a civil complaint or demand for arbitration is filed.

(3) If an action is tried in a civil court or arbitrated, the attorney representing the plaintiff or claimant may file a motion with the court or arbitrator for a contingency fee in excess of the percentage stated in paragraph (2), which motion shall be filed and served on all parties to the action and decided in the court’s discretion based on evidence establishing good cause for the higher contingency fee.

The limitations shall apply regardless of whether the recovery is by settlement, arbitration, or judgment, or whether the person for whom the recovery is made is a responsible adult, an infant, or a person of unsound mind.

(b) If periodic payments are awarded to the plaintiff pursuant to Section 667.7 of the Code of Civil Procedure, the court shall place a total value on these payments based upon the projected life expectancy of the plaintiff and include this amount in computing the total award from which attorney’s fees are calculated under this section.

(c) For purposes of this section:

(1) “Recovered” means the net sum recovered after deducting any disbursements or costs incurred in connection with prosecution or settlement of the claim. Costs of medical care incurred by the plaintiff and the attorney’s office-overhead costs or charges are not deductible disbursements or costs for such purpose.

(2) “Health care provider” means any person licensed or certified pursuant to Division 2 (commencing with Section 500), or licensed pursuant to the Osteopathic Initiative Act, or the Chiropractic Initiative Act, or licensed pursuant to Chapter 2.5 (commencing with Section 1440) of Division 2 of the Health and Safety Code; and any clinic, health dispensary, or health facility, licensed pursuant to Division 2 (commencing with Section 1200) of the Health and Safety Code. “Health care provider” includes the legal representatives of a health care provider.

(3) “Professional negligence” is a negligent act or omission to act by a health care provider in the rendering of professional services, which act or omission is the proximate cause of a personal injury or wrongful death, provided that the services are within the scope of services for which the provider is licensed and which are not within any restriction imposed by the licensing agency or licensed hospital.