California Code, Welfare and Institutions Code - WIC § 17852

(a) The state, a city, county, city and county, or hospital district may collect information for the purposes of this part only as required to assess eligibility for, or to administer, public services or programs.  This shall include coordinating services or programs across state and local agencies, ensuring that public services or programs adequately service individuals and diverse communities, enforcing civil rights protections, and providing access to services, programs, or benefits for which an individual may be eligible or that address needs for health, social, or other services.  This section shall include third parties under contract with a public officer or agency.

(b) All types of information, whether written or oral, concerning a person made or kept by any public officer or agency for the purpose of assessing eligibility for, or administering the services authorized by, this part are exempt from disclosure under the California Public Records Act (Division 10 (commencing with Section 7920.000) of Title 1 of the Government Code), are confidential, and shall not be disclosed except as required to administer the services or as required by law, as required by a federal or state court order, or to the state or local public health officer to carry out the duties of investigation, control, or surveillance of disease, as determined by the state or local public health agency.

(c) This section shall not prohibit the sharing of data as long as it is disclosed in a manner that could not be used to determine the identities of the persons to whom the data pertains, alone, or in combination with other data.

(d) This section shall not prohibit the sharing of personal information when the subject of that information has provided signed, written consent allowing the information to be provided to the person requesting the information.