Many initiatives have been carried out by governments around the world which have aimed to define common ICT standards for the public sector. However, the majority of data exchange conducted among public administrations is still based on paper or proprietary data formats. Public ICT is therefore lacking integration. The widespread use of common standards is especially hard to achieve in federally organized countries. Determinants for the adoption of common data exchange standards in such countries are identified in this paper. A conceptual model is drawn from a review of the literature and analyzed in a qualitative case study which is carried out in 13 municipalities of the German federal system. Seven determinants for the adoption of data exchange standards are identified. The paper concludes with practical implications on how the adoption of common data exchange standards can be increased.