California Code, Code of Civil Procedure - CCP § 2032.640

A party receiving a demand for a report under Section 2032.610 is entitled at the time of compliance to receive in exchange a copy of any existing written report of any examination of the same condition by any other physician, psychologist, or licensed health care practitioner. In addition, that party is entitled to receive promptly any later report of any previous or subsequent examination of the same condition, by any physician, psychologist, or licensed health care practitioner.