The study provides an overview of existing policies and practices in EU Member States and Norway towards third-country nationals in a prolonged situation of irregular stay. The study focuses on those third-country nationals subject to a return decision but whose return was not enforced or was postponed, and on those without a return decision who are unknown to the authorities. The study looks into national legislative framework and policies towards irregular migrants. It maps approaches to different types of services for this category of migrants and their provision. It describes the ways of ending the long-term irregular stay. Finally, it deals with the challenges and future measures to address the situation of long-term irregular migrants that could be implemented at the EU level. The chapters also reflect on the pandemic situation.