In two recent cases the Court of Justice has considered the impact of Union citizenship on the long-standing issue of the exportability of social security payments. These decisions clarify (i) the position of the Court in relation to the material scope of the protection provided by Article 18 EC, i.e. that the exercise of free movement is itself sufficient to bring an issue within the scope of the Treaty regardless of whether the issue actually in dispute involves a question of Community law and (ii) that the Court will examine residence requirements as a restriction on the freedoms conferred by Article 18 EC and as obstacles to freedom of movement. However, the fact that the Court came to different conclusions on the facts of the cases highlights the growing importance of the concept of justification of restrictions on citizens' rights to free movement and the challenge of developing a clear and consistent approach to its interpretation.