This chapter looks at the impact of external differentiation in terms of European Union (EU) citizenship and free movement rights. Using the European Economic Area (EEA) Agreement and EEA-non-EU citizens as one of the case studies, it shows how free movement activates a form of quasi-EU citizenship, placing these free movers on equal footing with EU citizens in all aspects but one - voting rights. In contrast, Brexit and the decoupling of the EU citizenship status from free movement rights on the territory of the United Kingdom (UK) will imply a de facto loss of EU citizenship. In light of this, I propose the concept of semi-EU citizenship for the EU citizens residing in the post-Brexit UK. Their case reflects the consequences of EU differentiated disintegration in terms of rights loss and status deterioration. The chapter is based on the analysis of the agreements governing EU citizenship and free movement rights in these two cases and demonstrates that the link between the status of EU citizen and the free movement rights can be severed.