This book provides an in-depth analysis of the effectiveness of legal protection in the composite procedures in place within the Single Supervisory Mechanism (SSM), established to ensure an effective prudential banking supervision within the euro area. This system, in which the European Central Bank and national prudential banking supervisors closely cooperate, results in a far-reaching shared administration entailing supervisory decisions based on complex composite administrative procedures which involve both EU and national legal orders. The current system of legal protection seems not yet fully-fledged to the reality of increasingly far-reaching forms of shared administration for the implementation of EU law. This book addresses the tension between ensuring effective supervision, by means of a shared administration, and ensuring effective legal protection in composite administrative procedures. To arrive at a meaningful discussion of the SSM's far-reaching shared administration, it categorizes the composite procedures in place within the SSM in such a way that other shared administrations in fields of law such as the European Structural Funds, fisheries, and the Single Resolution Mechanism may also benefit from its insights. The book not only discusses the challenges for the effectiveness of legal protection within the SSM, but also seeks to provide solutions within the current EU system of legal remedies and procedures as well as possible long-term solutions.