At present, the scope of application of social security law provisions is undergoing changes in connection with the development of new social relations, the emergence of new forms of using non-independent labor, and the modification of forms of labor organization and labor management. It has been established that the codification of the branch must be preceded by the need to resolve issues related to the definition of the “boundaries” of the subject of the branch of social security law, the relationship of its provisions with the provisions of other branches of law in related areas of legal regulation.