In the system of German federalism, the administrations of the 16 federal states (Länder) have central responsibility for the enforcement of both federal and state law. Despite all the heterogeneity in terms of size, administrative tradition and culture, their administrative structures are relatively uniform. Everywhere, the municipalities, which are part of the state executive under state law, play a significant and, above all, independent role as bodies of the public administration. There are some differences, but administration seems in some respects relatively homogeneous, not least due to the largely similar staffing structures, career patterns and administrative cultures. Structural reforms of very different scopes have been a long-term phenomenon since the 1990s.