The article analyzes the publications devoted to the reform of the health care financing system in Russia, as well as determines the place and tasks of rendering paid services in the structure of the budget of medical and preventive institutions. The study reveals the insufficient knowledge of problems of transition to a new system from the point of view of the physicians. The paper presents the results of applied sociological research using expert interviews that reveal the problems of interaction between a physician and a patient in the provision of paid medical services in a single-channel financing system.