California Code of Civil Procedure
(a) No action based upon the health care provider’s professional negligence may be commenced unless the defendant has been given at least 90 days’ prior notice of the intention to commence the action.
(b) No particular form of notice is required, but it shall notify the defendant of the legal basis of the claim and the type of loss sustained, including with specificity the nature of the injuries suffered.
(c) The notice may be served in the manner prescribed in Chapter 5 (commencing with Section 1010) of Title 14 of Part 2.
(d) If the notice is served within 90 days of the expiration of the applicable statute of limitations, the time for the commencement of the action shall be extended 90 days from the service of the notice.
(e) The provisions of this section shall not be applicable with respect to any defendant whose name is unknown to the plaintiff at the time of filing the complaint and who is identified therein by a fictitious name, as provided in Section 474.
(f) For the purposes of this section:
(1) “Health care provider” means any person licensed or certified pursuant to Division 2 (commencing with Section 500) of the Business and Professions Code, 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;
(2) “Professional negligence” means 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 such 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.