‘Social investment’ as an idea to justify social policy reforms has become more and more accepted in recent years and has decisively shaped agenda setting and policy formulation in European welfare states. The effectiveness of this new welfare state model, however, depends highly on the capacity to provide social services. Social services – job training, counselling and support for care work – are a key component of the social investment model. Drawing on the policy capacity approach, the article provides an analytical framework to study the ‘operational core’ of the social investment state. This implementation perspective allows us to assess whether governance actors actually have the resources to fulfil the social investment idea of enhancing citizens’ freedom to act. Empirically, the article concentrates on two selected European welfare states, Germany and France, countries with similar welfare systems but very different politico-administrative systems, and on two fields of social service provision that are addressed differently in the social investment debate: early childhood education and care (ECEC) and elderly care. Empirically, we use systematic content analysis to intensively study policy documents and secondary analyses. We show that both countries (still) lack policy capacities in these two sectors as a basis for resilient implementation of the social investment paradigm.