In the German school and education system, questions regarding the structure, function, and significance of civic engagement in civil society organizations such as clubs are gaining increasing importance. Against the backdrop of current debates about civic engagement and clubs in Germany, the study focuses on the structural peculiarities and practices of school support associations. For this purpose, a school-related special evaluation of the nationwide representative volunteer surveys from 1999 to 2009 was combined with a quantitative survey of associations and qualitative interviews with officials from school support associations. The analyses show that over the past two decades, a far-reaching civil society infrastructure has been established and differentiated within the German school system, with school support associations playing a particularly important role.