This book chapter aims to determine the reference group benefitting from transnational social protection in the EU by applying the Coordination Regu-lations.This assumes a methodologically correct measurement of the number of persons covered by the Coordination Regulations (i.e., the entire group of persons in a cross-border situation that falls under the personal scope of the Coordination Regulations) as well as the number of mobile persons in the EU who claimed their social rights through the application of it. Furthermore, this chapter aims to quantify Member States’ expenditure on transnational social protection by applying the Coordination Regulations and to compare this with total social spending. The focus is on the main branches of social security, namely, pensions, healthcare, and family benefits. The latter is often linked to benefit tourism and financial unfairness. Regarding healthcare, the data analysed is limited to the provision of cross-border healthcare. The analysis of the social security branches of pensions and family benefits mainly focuses on the exportability of these social benefits. However, the scope and, thus, the impact of the Coordination Regulations is much broader than its exportability dimension. Particularly, there is the question of access to social security benefits when moving to another Member State, its take-up (and differences with native citizens), and its financial consequences for national welfare states. Such figures are not reported. Finally, this book chapter only provides an overview of social security benefits paid to mobile persons and, therefore, does not provide an overview of the receipts of Member States from social security contributions paid by mobile persons and their employers. Before turning to the figures, the following sections briefly describe the concept of transnational social protection and the legal framework that facilitates this protection in the EU, primarily focusing on the Coordination Regulations.