The purpose of this paper is to examine: the content of radical change by mapping differences between two templates for organizing delivery of healthcare; the enabling and constraining mechanisms underlying major change from one template to another; and the processes implicated in change implementation. Longitudinal, qualitative case study design allowed the tracking, over a four-year period, of the transformation of healthcare service in a community from provider-centered, fragmented delivery to patient-centered, integrated delivery. The authors conducted 90 interviews at three intervals, observed meetings, and analyzed internal and external documents. Concepts on content, process and mechanisms were used to analyze the data. Transition from one template to another involves radical change in structures/systems and underlying values. Mechanisms precipitating and enabling change include: powerful stakeholders' dissatisfaction with current template and commitment to a new one, willingness to resource the change, provision of credible leadership, and manipulation of incentive programs. Radical change is underlain by a series of micro change processes that involve emergent, non-linear dynamics, and that follow their own track with enabling and constraining mechanisms. The paper describes a case of positive, successful change. Implications include importance of: attention to power dynamics, persistent leadership, elimination of boundaries between collaborating groups, and aligning incentives with desired practice changes; and attending to both variance and process in understanding healthcare change.