This paper is an attempt to connect the internal and the external aspects in the transformation  of citizenship, building on Christian Joppke's hypothesis on the 'lightening of citizenship'.  Taking social policy developments in the EU as an example, the paper contends that  lightening of citizenship entails universalization and lightening of social policy. It also highlights  the leading role of the CJEU in this transformation.  Substantially, we argue that universalisation and lightening of social security corresponds  to functional requirement of the internal market and the increasingly diversified life  career of its citizenry. In this regard, 'lightening' should be conceptually separated from mere  'retrenchment'. This direction has been augmented by the intervention of the ECJ, whose  judgements has built on the Union Citizenship and enhanced individual social rights protection.  Featuring citizenship as a universal status, however, individual rights can be protected,  but collective ordering of social relations would take a back seat.