Cal. Education Code § 35331

(a) The governing board of any school district conducting excursions and field trips pursuant to this article shall provide, or make available, medical or hospital service, or both, for pupils of the district injured while participating in any excursion or field trip under the jurisdiction of, or sponsored or controlled by, the district or the authorities of any school of the district. (b) (1) The medical or hospital service, or both, described in subdivision (a) shall be provided, or made available, through any of the following: (A) One or more nonprofit membership corporations defraying the cost of medical or hospital service, or both. (B) One or more group, blanket, or individual policies of accident insurance from an authorized insurer. (C) A self-insurance program of the school district. (2) The cost incurred by the school district pursuant to this subdivision may be paid from the funds of the district, or by the insured pupil or his or her parent or guardian. (3) The membership may be taken in, or the insurance may be purchased from, only those corporations or insurers that are authorized to do business in this state. If the coverage described in this subdivision is to be provided through a self-insurance program of the school district, claims may be paid from a fund established for that purpose.