Cal. Business and Professions Code § 2395.5

(a) A licensee who serves on an on-call basis to a hospital emergency room, who in good faith renders emergency obstetrical services to a person while serving on-call, shall not be liable for any civil damages as a result of any negligent act or omission by the licensee in rendering the emergency obstetrical services. The immunity granted by this section shall not apply to acts or omissions constituting gross negligence, recklessness, or willful misconduct. (b) The protections of subdivision (a) shall not apply to the licensee in any of the following cases: (1) Consideration in any form was provided to the licensee for serving, or the licensee was required to serve, on an on-call basis to the hospital emergency room. In either event, the protections of subdivision (a) shall not apply unless the hospital expressly, in writing, accepts liability for the licensee’s negligent acts or omissions. (2) The licensee had provided prior medical diagnosis or treatment to the same patient for a condition having a bearing on or relevance to the treatment of the obstetrical condition which required emergency services. (3) Before rendering emergency obstetrical services, the licensee had a contractual obligation or agreement with the patient, another licensee, or a third-party payer on the patient’s behalf to provide obstetrical care for the patient, or the licensee had a reasonable expectation of payment for the emergency services provided to the patient. (c) Except as provided in subdivision (b), nothing in this section shall be construed to affect or modify the liability of the hospital for ordinary or gross negligence.