A scientific article is devoted to the formation of personnel reserves in the system of public power, understanding the conceptual foundations, parameters, and criteria that determine the effectiveness of their formation and use. Based on the analysis of managerial practices at both the federal and regional levels, key problem areas, factors and conditions that affect the processes of the institutionalization of personnel reserves are identified. The article presents the results of sociological research, an analysis of the practice of forming personnel reserves in the context of sociocultural dynamics, and transformation processes in the public administration system, and defines the features of reservist motivation, the level of readiness for self-development, personal and professional mobility, and career expectations. The authors disclose the issues of conceptual, methodological and technological support for personnel reserve management through the prism of the maturity of personnel technologies, and justify that the management of personnel reserves in the public sphere goes beyond the exclusively organizational context and integrates into a macro-social context. Based on the analysis, the authors propose a vision of new conceptual approaches and principles for developing personnel reserves in the public sphere in the framework of implementing national priorities and strategic goals of the country's sustainable development.