The article is devoted to the theoretical and legal understanding of the subject of administrative law in the context of the transformation of public administration. The author identifies the limitations of the traditional model, which reduces the subject of the industry to the regulation of relations in the field of executive power, and offers an expanded understanding covering public administrative activities regardless of the formal status of its subjects. The article substantiates the inclusion of relations with the participation of local governments, state corporations and other public legal entities in the sphere of administrative regulation. A comparative analysis with the German doctrine reveals the common features of the functional approach. The novelty lies in the development of a concept that takes into account the institutional and functional diversity of public authorities in the modern management system, as well as the place of organizational activity, including those of a related, auxiliary, accompanying and complementary nature.