The environment of national agencies has changed considerably in recent years as they increasingly become engaged in European Union networks. This article contributes to a growing body of literature on those networks and their effect on executive politics at the national level by asking whether and how the EU involvement of national agencies affects the agencies' autonomy in policy formulation. We develop an analytical model for explaining the effect of EU involvement on agency autonomy. Analyzing data from a comprehensive survey of federal agencies in Germany, we find that EU involvement has a positive effect on national agencies' policy autonomy. Moreover, we find a somewhat stronger effect of agency involvement in sectoral networks on autonomy than in intergovernmental networks, which is attributed to information asymmetries between ministries and agencies. Yet this effect is weaker than initially expected, which can be explained by a considerable degree of overlap between different types of EU involvement.