This paper examines how the distribution of social goods within a political community relates to decisions on membership boundaries. The author challenges two renowned accounts of such a relation: firstly, Walzer’s account according to which decisions on membership boundaries necessarily precede decisions on distribution; secondly, Benhabib’s account, according to which membership boundaries can be called into question on the basis of universalist claims. Departing from both accounts, the author concludes that actual changes in the pool of participants in practices of creation and exchange of social goods pressure a political community to redefine its distributive patterns and, accordingly, the boundaries of its formal political membership. This claim will be supported by the analysis of threshold cases decided by the EU Court of Justice, in which EU citizenship is invoked with the atypical purpose of granting rights to a specific group of non-formal members. The reason for extending the protection provided by EU citizenship to these non-formal members is that they are already deeply embedded in practices of creation and exchange of social goods that concur to realise the distributive plan to which the EU is committed.