California Code, Civil Code - CIV § 3333.1

(a) In the event the defendant so elects, in an action for personal injury against a health care provider based upon professional negligence, he may introduce evidence of any amount payable as a benefit to the plaintiff as a result of the personal injury pursuant to the United States Social Security Act,  1 any state or federal income disability or worker's compensation act, any health, sickness or income-disability insurance, accident insurance that provides health benefits or income-disability coverage, and any contract or agreement of any group, organization, partnership, or corporation to provide, pay for, or reimburse the cost of medical, hospital, dental, or other health care services. Where the defendant elects to introduce such evidence, the plaintiff may introduce evidence of any amount which the plaintiff has paid or contributed to secure his right to any insurance benefits concerning which the defendant has introduced evidence.

(b) No source of collateral benefits introduced pursuant to subdivision (a) shall recover any amount against the plaintiff nor shall it be subrogated to the rights of the plaintiff against a defendant.

(c) For the purposes of this section: