“Telephone medical advice service” means any business entity that employs, or contracts or subcontracts, directly or indirectly, with, the full-time equivalent of five or more persons functioning as health care professionals, whose primary function is to provide telephone medical advice, that provides telephone medical advice services to a patient at a California address. “Telephone medical advice service” does not include a medical group that operates in multiple locations in California if no more than five full-time equivalent persons at any one location perform telephone medical advice services and those persons limit the telephone medical advice services to patients being treated at that location.