This paper provides a tool for municipio government managers, other stakeholders, and state and federal planners to assess the potential size and complexity of prospective GIS’s both for individual municipios and for groups of municipios. It presents a quantitative model to estimate the potential size/complexity of adopting GIS in a municipio or municipios. It summarizes attributes characterizing the population, labor force, education, housing stock, utility link-ups and other factors that reflect the magnitude of potential GIS applications.