Using the comparative contextual framework of HRM, we investigate the effects of external and internal context on HRM systems. Further, we add HRM’s organizational integration that pre-sumably fosters the adoption of context-specific HRM systems. We draw on data from 4,768 organizations across 34 countries and analyze the similarity of HRM systems with distance matri-ces, a widely used approach in geographic science. Our results show that both external and inter-nal context affect (dis)similarity of HRM systems and highlight that organizations that operate in a similar institutional environment have more similar HRM systems. Furthermore, we find that devolvement of HRM activities from HRM to line management leads to less similarity of HRM practices between organizations. Future research needs to take a broad set of context dimensions as well as the role of the HRM department into account and also include organizational power dynamics.