The article outlines the results of the study on the socio-psychological phenomenon of co-opetition in a healthcare administrator’s career. The main sample of the empirical study was comprised of 150 healthcare system employees (76 managers and 74 employees in medical institutions). The research focuses on the socio-psychological phenomenon of co-opetition, which combines the concepts of “competition” and “cooperation”. The meaning of the term “co-opetition” in social interaction is defined on the example of healthcare staff. The article addresses the importance of the individual and the social components in the career achievements of medical institution managers and offers a definition of the word “career”. The article presents the main results of an empirical socio-psychological study, which allow us to determine the type of behaviour the respondents exhibit in situations of conflict of interest and personal behavioural strategies for resolving competitive or conflict situations. The work substantiates a new view on co-opetitive social interaction which is determined by a combination of interpersonal relationships aimed at cooperation with the participants of the process and, at the same time, associated with the behavioural strategy aimed at achieving one’s personal goals — competition. We also present a psychological substantiation of the “career plateau” phenomenon in the career of medical workers. Having substantiated the emergence of the “career plateau”, we describe its features as well as the ways to overcome its effects. The study revealed that the focus on co-opetitive behaviour results in the absence of the “plateau” in a professional’s career and is characteristic to a greater extent for male healthcare managers. The research results indicate that co-opetition as a component of social behaviour has certain advantages in comparison with pure competition or cooperation. We identify the features of individual propensity for co-opetition among the healthcare system managers, which affect their career achievements, and describe the gender differences in the co-opetitive relationship features and how these differences are reflected in the development of a “career plateau”. The overall outcome of the research suggests that the focus on co-opetitive behaviour contributes to higher professional career achievements.