Norway is committed to a high quality and equitable education system, as demonstrated by its high level of public expenditure on education and the dynamic policy activity targeting education quality. Despite progress made in enhancing average student performance in recent years, there still are significant differences between schools in municipalities and between municipalities and regions. In response, Norway has started to implement the new competence development model that sets out to develop teacher professionalism with in-service professional development. With this new policy, the Government of Norway aims to provide municipalities and schools with greater freedom of action and empower them to carry out systematic school improvements at the local level. This decentralised approach would respond to local context and the diversity of needs between Norwegian schools. This report aims to support Norway in this effort, analysing the features of the new model, the engagement of the different stakeholders and the policy context for its introduction. Building on the OECD implementation framework, the report proposes concrete actions to adapt the implementation strategy for impact. The report will be valuable not only for Norway, but also to the many countries that are looking to promote school-based professional development and bridge the gap between policy design and effective implementation.