Issues of the effective financing the health system remain relevant for many countries, including Russia. The reform of the national health care system continues, and after switching to singlechannel financing, not only its advantages but also its shortcomings became visible. The main objective of insurance medicine is to increase the interest of health workers in the final results of their work - to treat patients. However, this task is obviously associated with financing, providing for the renewal of equipment and tools, upgrading the skills of medical workers and purchasing all necessary drugs. This article is of an overview nature and is aimed at considering the specifics of financial flows in the system of compulsory medical insurance with its single-channel financing. The article analyzes and systemizes strengths and weaknesses of single-channel financing of medical services in the framework of compulsory health insurance. The main conclusion is the authors’ opinion that the role of insurance companies in the system of compulsory medical insurance is to analyze accounts of medical organizations and transfer money to their accounts, while the responsibility for the results of treatment is completely borne by medical workers.