California Code, Health and Safety Code - HSC § 1367.665

(a) A health care service plan contract, except for a specialized health care service plan contract, that is issued, amended, delivered, or renewed on or after July 1, 2000, shall be deemed to provide coverage for all generally medically accepted cancer screening tests, subject to all terms and conditions that would otherwise apply.

(c) For purposes of this section, “biomarker test” means a diagnostic test, such as single or multigene, of the cancer patient's biospecimen, such as tissue, blood, or other bodily fluids, for DNA or RNA alterations, including phenotypic characteristics of a malignancy, to identify an individual with a subtype of cancer, in order to guide patient treatment.

(d) Notwithstanding subdivision (b), this section does not prohibit a health care service plan from requiring prior authorization on biomarker testing that is not for an FDA-approved therapy for advanced or metastatic stage 3 or 4 cancer.

(e) This section does not limit, prohibit, or modify an enrollee's rights to biomarker testing as part of an approved clinical trial under Section 1370.6.