To promote and facilitate free movement in the European Union, Directive 2004/38 provides a generous regime for family reunification for EU citizens who move to a Member State of which they are not a national. In Ruiz Zambrano, the European Court of Justice established a right to family reunification for citizens who reside in the Member States of which they are a national on the basis of art.20 TFEU if the refusal of such a right would deprive them of the genuine enjoyment of the substance of their rights as European citizens. A legal framework to determine the limits and conditions under which this right can be exercised is lacking, however. This article investigates these limits and conditions through an analysis of the case law concerning art.20 TFEU. To shape this inquiry, a comparison is made between family reunification rights awarded by Directive 2004/38 and those derived from art.20 TFEU. The last part of the analysis explores the role of the right to family life in the art.20 TFEU case law, and compares the protection of family life it offers to the threshold of art.8 ECHR.