As the magical date December 31, 1992 is drawing closer full economic integration in the European Community is becoming a reality. At the same time it is getting clear that the future economic union has no social counterpart. International, as well as European social security law has been developed along the lines of two different techniques: co-ordination and harrnonization. While the former technique leaves the national legislation intact, only regulating cases with international aspects, the latter does have consequences for national law. The co-ordination of national social security law within the European Community is ruled by co-ordination Regulations 140817 1 and 574172. The mere amendment of the existing Regulations seems insufficient to create a social dimension within the European Community.Moreover, the co-ordination technique seems handicapped by its intrinsical complexity. A genuine harmonization, on the other hand, seems both for political and technical reasons impossible in the short run. The Thirteenth State scenario aims both at offering an alternative for the complexity of co-ordination and providing a first impetus towards harmonization. This scenario was elaborated by a team of specialists at the University of Leuven, Belgium. The result of this research is an extensive blue-print for a European Community social insurance scheme.The authors offer an overview of the main goals of the scenario and a number of basic choices that have been made in develop-ing it. Finally they give some comments on the legal grounds for a European social insurance scheme and on the problems concerned with the elaboration of the administrative structure for such a scheme.