Health care service plans shall, upon rejecting a claim from a health care provider or a patient, and upon their demand, disclose the specific rationale used in determining why the claim was rejected. Nothing in this section is intended to expand or restrict the ability of a health care provider or a patient from having health care coverage approved in advance of services.
Source:
Section 1399.55, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=HSC§ionNum=1399.55..