Cal. Penal Code § 1543

(a) Records of the identity, diagnosis, prognosis, or treatment of any patient maintained by a health care facility which are not privileged records required to be secured by the special master procedure in Section 1524, or records required by law to be confidential, shall only be disclosed to law enforcement agencies pursuant to this section:
1. (1) In accordance with the prior written consent of the patient; or
2. (2) If authorized by an appropriate order of a court of competent jurisdiction in the county where the records are located, granted after application showing good cause therefor. In assessing good cause, the court:
  1. (A) Shall weigh the public interest and the need for disclosure against the injury to the patient, to the physician-patient relationship, and to the treatment services;
  2. (B) Shall determine that there is a reasonable likelihood that the records in question will disclose material information or evidence of substantial value in connection with the investigation or prosecution; or
3. (3) By a search warrant obtained pursuant to Section 1524.
(b) The prohibitions of this section continue to apply to records concerning any individual who has been a patient, irrespective of whether or when he or she ceases to be a patient.
(c) Except where an extraordinary order under Section 1544 is granted or a search warrant is obtained pursuant to Section 1524, any health care facility whose records are sought under this chapter shall be notified of the application and afforded an opportunity to appear and be heard thereon.
(d) Both disclosure and dissemination of any information from the records shall be limited under the terms of the order to assure that no information will be unnecessarily disclosed and that dissemination will be no wider than necessary.
This chapter shall not apply to investigations of fraud in the provision or receipt of Medi-Cal benefits, investigations of insurance fraud performed by the Department of Insurance or the California Highway Patrol, investigations of workers’ compensation insurance fraud performed by the Department of Corrections and conducted by peace officers specified in paragraph (2) of subdivision (d) of Section 830.2, and investigations and research regarding occupational health and safety performed by or under agreement with the Department of Industrial Relations. Access to medical records in these investigations shall be governed by all laws in effect at the time access is sought.
(e) Nothing in this chapter shall prohibit disclosure by a medical facility or medical provider of information contained in medical records where disclosure to specific agencies is mandated by statutes or regulations.
(f) This chapter shall not be construed to authorize disclosure of privileged records to law enforcement agencies by the procedure set forth in this chapter, where the privileged records are required to be secured by the special master procedure set forth in subdivision (c) of Section 1524 or required by law to be confidential.