In the last 20 years, publicly provided social services – a pillar of the Post-WW2 welfare states – have experienced significant restructuring throughout Europe. An important stream of research emphasizes the socially innovative impact of many restructuring experiences in specific social services and territorial contexts. In particular, great expectations are placed on the devolution of authority from the central state to local governments, the growing role of the third sector, and the increasing involvement of users, for their positive consequences in terms of response to needs, empowerment and democratic governance. However, these expectations are not fully supported by empirical evidence, some of which highlights how the growing stratification of supply is bringing about inequalities in access and quality, undermining the principle of social citizenship. Innovation in social services may thus involve new forms of social and territorial exclusion. While questioning the mainstream notion of social innovation, the paper argues that a new research agenda should address the challenge of conjugating social innovation with universal social rights and citizenship, through a renewed role for the state.