This paper tackles the ongoing debate over the adoption of EU legislation on institutional design requirements for NCAs by clarifying the status quo. It is argued that EU law already imposes wide-ranging obligations upon Member States when deciding how to set up their NCAs, especially on the basis of the principle of effectiveness. To arrive at that conclusion, a summary of existing institutional design requirements for national regulators in other areas of EU law is provided, and the legal basis for the imposition of such requirements is discussed. By extrapolating and drawing analogies from EU case-law relating to competition law and other areas of EU law, it will be shown that we already have a vast body of judicial clarifications of the precise extent of institutional design requirements for NCAs. Nonetheless, it will also be argued that secondary legislation on this issue is crucial for legal certainty and effectiveness.