The Policies are based upon a review of the available clinical information including clinical outcome studies in the peer-reviewed published medical literature, regulatory status of the drug or device, evidence-based guidelines of governmental bodies, and evidence-based guidelines and positions of select national health professional organizations. Health Net's National Medical Policies (the 'Policies') are developed to assist Health Net in administering plan benefits and determining whether a particular procedure, drug, service, or supply is medically necessary.