The article describes the issue of deinstitutionalisation policy in the area of social assistance in the European Union (EU). It presents the genesis, context and evolution of this policy. Based on the analysis of materials available on the official websites of the European Commission (EC), it addresses the issues involved in the assumptions of the deinstitutionalisation policy, its main stakeholders, the place it occupies in EU priorities, implementation instruments and ways of setting the boundaries of deinstitutionalisation in the area of social assistance. It discusses terminological issues, including sociological interpretations of the concept of deinstitutionalisation and the resulting connotations with Erving Goffman’s concept of total institution. It analyses the most important documents related to addressing these issues at the EU level and their implementation. It also contains selected important elements involved in monitoring and evaluating deinstitutionalisation processes in Member States before the coronavirus pandemic, considered from the perspective of common indicators for children, children with disabilities, adults with disabilities, adults with mental health problems and seniors. It presents the main barriers, trends and challenges of deinstitutionalisation processes in the EU.