Existing law, the Knox-Keene Health Care Service Plan Act of 1975, provides for the licensure and regulation of health care service plans by the Department of Managed Health Care and makes a willful violation of the act a crime. Existing law provides for the regulation of health insurers by the Department of Insurance. Existing law generally prohibits a health care service plan, excluding a Medi-Cal managed care plan, or health insurer from subjecting antiretroviral drugs that are medically necessary for the prevention of HIV/AIDS, including preexposure prophylaxis or postexposure prophylaxis, to prior authorization or step therapy. Under existing law, a health care service plan or health insurer is not required to cover all of the therapeutically equivalent versions of those drugs without prior authorization or step therapy if at least one is covered without prior authorization or step therapy.