Chapter 16 has the purpose of defining the theoretical framework for the analysis of the establishment of central purchasing bodies at the regional level and their impact both on the national health service and on the market. The chapter is the seminal work of the CERGAS / SDA Bocconi Observatory on Management of Healthcare Procurement (MASAN). We initially carried out desk data collection from online sources (websites, reports) regarding regional purchasing bodies involved in healthcare procurement. In addition to the desk analysis, we investigated central purchasing organizations in four Italian Regions: Lombardy, Tuscany, Campania and Sicily. Cases were described through semi-structured interviews and analysis of the documentation. The four cases where chosen because of their relevance. The analysis shows that centralization consisted predominantly in aggregating administrative functions and tender procedures. Existing available data do not allow for assessing the actual policy, nor the optimality, for example, of the level of aggregation of the demand. However, it is clear that despite the effort to standardize contracts, there is high variability in the institutional and organizational settings that have been adopted by different Italian regions. This demonstrates that the definition of the purchasing function is the result of the reference context and cannot, in some respects, be standardized. In the future, even in the face of reorganization of the healthcare system, the real issue will no longer be the reorganization of the purchasing process, but the definition of a strategic governance of healthcare expenditure. The choice of the centralization model must be coherent with the maturity of the regional healthcare system and require a strong political commitment.