This paper aims to analyze changes in the relationship between the State and the Union when it comes to implementing public policies in social service. The implementation of the universal social service system (Sistema Único de Assistência Social, SUAS) has stimulated a change in the way state governments act. They are now taking a role as mediators between federal and municipal governments. In order to deal with this newly formed relationship, new administrative structures were created such as the Comissão Intergestores Tripartite (CIT). Following the study of materials related to federalism and program implementation this paper aims to show that the State still faces challenges in dealing with new administrative structures, potentially jeopardizing the implementation of public policies in the social service sector.