This article describes an IT-based, eGov-centered and capability-driven model for assessing e-government capabilities and maturity of public agencies. It is the result of an initiative of the Chilean government to reinforce its e-government strategy. The proposed model, called eGov-MM (e-Government Maturity Model), has three dimensions (a cube) supporting business processes: information criteria, IT resources, and leverage domains. Changing the traditional and exclusive focus on IT, four Leverage Domains are defined: e-Strategy, IT Governance, Process Management, and People and Organization Capabilities. The Leverage Domains generate a hierarchical structure with a second level named Key Domain Areas. These areas should be measurable and controllable, so they are related to a third hierarchical level, called Critical Variables, allowing the model's elements to be assessed qualitatively and quantitatively. The capability and maturity of these variables associated with the intersection with the other two axes of the cube establish five levels of capability. The proposed model is strongly supported by the international experience and best practices for IT management and has already been field tested.