The thesis analyses the EU-level policy process on “Social Services of General Interest” over more than a decade. The author identifies the factors that can explain the development and state of play of the EU-level legal, policy, and quality frameworks at the end of 2016. He elaborates on relevant theories, concepts, and political discourses, and looks into the role and initiatives of the EU Member States and the European Commission as the key policymakers. The thesis analyses the reasons and implications for the organisation, provision, and financing of social services that stem from the overarching or recalibration of national policy arenas and scopes by the internal market and the EU policy context.