California Code, Health and Safety Code - HSC § 1365.5

(a) No health care service plan or specialized health care service plan shall refuse to enter into any contract or shall cancel or decline to renew or reinstate any contract because of the race, color, national origin, ancestry, religion, sex, marital status, sexual orientation, or age of any contracting party, prospective contracting party, or person reasonably expected to benefit from that contract as a subscriber, enrollee, member, or otherwise.

(b) The terms of any contract shall not be modified, and the benefits or coverage of any contract shall not be subject to any limitations, exceptions, exclusions, reductions, copayments, coinsurance, deductibles, reservations, or premium, price, or charge differentials, or other modifications because of the race, color, national origin, ancestry, religion, sex, marital status, sexual orientation, or age of any contracting party, potential contracting party, or person reasonably expected to benefit from that contract as a subscriber, enrollee, member, or otherwise; except that premium, price, or charge differentials because of the age of any individual when based on objective, valid, and up-to-date statistical and actuarial data are not prohibited.

(c) It shall be deemed a violation of subdivision (a) for any health care service plan to utilize marital status, living arrangements, occupation, sex, beneficiary designation, ZIP Codes or other territorial classification, or any combination thereof for the purpose of establishing sexual orientation. Nothing in this section shall be construed to alter in any manner the existing law prohibiting health care service plans from conducting tests for the presence of human immunodeficiency virus or evidence thereof.

(d) This section shall not be construed to limit the authority of the director to adopt or enforce regulations prohibiting discrimination because of sex, marital status, or sexual orientation.

(e) “Sex” as used in this section shall have the same meaning as “gender,” as defined in Section 422.56 of the Penal Code.

(f) The changes made to this section by the act adding this subdivision shall only apply to contracts issued, amended, or renewed on or after January 1, 2011.