[What is purchased, how and from whom by Seguro Popular in Mexico? Experience with strategic purchasing at national level and in a pioneer institution].

Objective:: To analyze the scope of demand subsidies through strategic purchasing of health services.

Materials and methods:: Interviews and document analyses at national level and a case study of the state of Hidalgo.

Results:: SPSS explicitly prioritizes interventions to be financed and regulates prices and expenditure ceilings. Public providers are predominantly funded through the purchasing of inputs and the contracting of human resources, in the absence of competition and with a low degree of managerial autonomy. Seguro Popular in Hidalgo has diversified service providers and payment mechanisms.

Conclusions:: SPSS has ample opportunity to extend and deepen strategic purchasing. Greater decision-making autonomy of payers and providers is required, as well as regulations to promote provider networks in competitive environments.