Objective: To develop an automated model for the operational regionalization needed in the planning of the health service networks proposed by the new Mexican health care model (Modelo Integrador de Servicios de Salud MIDAS).
Material and methods: Using available data for México during 2005 and 2007, a geospatial model was developed to estimate potential catchment areas around health facilities based on access travel time. The results were compared with an operational regionalization (ERO) study manually carried out in Oaxaca with 2005 data.
Results: The ERO assigned 48% of villages to health care centers further away than those assigned by the geospatial model, and 23% of these health centers referred patients to more distant hospitals.
Conclusions: The model calculated by this study generated a more efficient regionalization than the ERO model, minimizing travel time to access health services. This model has been adopted by the General Department of Health Planning and Development of the Mexican Ministry of Health for the implementation of the Health Sector Infrastructure Master Plan.