Since European Union (EU) enlargement in 2003, labour migration from East to West and South to North has increased. It is to be expected that a share of these workers will want to retire in their host countries. According to the academic literature, EU legislation protects such mobility well by allowing the transfer of rights accrued in any EU country to another. However, such research has focused on legislation, not outcomes. We know little about how migration will affect the financial status of retired migrants in their host country and their ability to sustain a life there, should they stay after retirement. Using migration, wage and pension policy data (Eurostat, Organisation for Economic Co-operation and Development), this paper projects the post-retirement incomes of a range of hypothetical EU migrants, selected in relation to the most common migratory flows since 2003. After having worked in their home countries (Romania, Poland, Bulgaria, Italy) for at least ten years, these people move to richer countries (Italy, Spain, Germany, United Kingdom) and work there for at least 30 years. To determine whether they can remain settled after decades of labour force participation in the host country, the paper adds their pension entitlements from home and host countries and compares this income with the relative poverty line of the host countries. This shows that good portability of entitlements matters little when these are very low because of a large wage gap between home and host country. Thus, after at least 30 years of enjoying all citizenship rights as workers, most of these individuals are projected to receive incomes below the relative poverty line of their host countries and thus experience a sharp drop in this status. Their citizenship is diminished. The paper concludes by considering policies that could avoid such an outcome.