Abstract Background Primary care, and its transformation into Primary Health Care (PHC), has become an area of intense policy interest around the world. As part of this trend Alberta, Canada, has implemented Primary Care Networks (PCNs). These are decentralized organizations, mandated with supporting the delivery of PHC, funded through capitation, and operating as partnerships between the province’s healthcare administration system and family physicians. This paper provides an implementation history of the PCNs, giving a detailed account of how people, time, and culture have interacted to implement bottom up, incremental change in a predominantly Fee-For-Service (FFS) environment. Methods Our implementation history is built out of an analysis of policy documents and qualitative interviews. We conducted an interpretive analysis of relevant policy documents (n = 20) published since the first PCN was established. We then grounded 12 semi-structured interviews in that initial policy analysis. These interviews explored 11 key stakeholders’ perceptions of PHC transformation in Alberta generally, and the formation and evolution of the PCNs specifically. The data from the policy review and the interviews were coded inductively, with participants checking our emerging analyses. Results Over time, the PCNs have shifted from an initial Frontier Era that emphasized local solutions to local problems and featured few rules, to a present Era of Accountability that features central demands for standardized measures, governance, and co-planning with other elements of the health system. Across both eras, the PCNs have been first and foremost instruments and supporters of family physician authority and autonomy. A core group of people emerged to create the PCNs and, over time, to develop a long-term Quality Improvement (QI) vision and governance plan for them as organizations. The continuing willingness of both these groups to work at understanding and aligning one another’s cultures to achieve the transformation towards PHC has been central to the PCNs’ survival and success. Conclusions Generalizable lessons from the implementation history of this emerging policy experiment include: The need for flexibility within a broad commitment to improving quality. The importance of time for individuals and organizations to learn about: quality improvement; one another’s cultures; and how best to support the transformation of a system while delivering care locally.