The “woolliness” and “methodological hurdles” of co-production make it challenging to compare and contrast different co-production policy initiatives and their outcomes, and distil “what works”, for whom and in what circumstances. Inspired by Nabatchi et al. (2017) 3Ws typology of the Who, When, and What of co-production, we draw on co-production theory deriving from a narrative literature review and empirical research of co-production cases in Scotland and Australia. We propose a new “5Ws” co-production framework of Who, When, What, Why, and Where, arguing that the context (where) should be an integral part of co-production analyses as socio-political, geographical conditions, and service settings influence the processes and outcomes of co-production, and that the reasons (why) behind co-production determine who is involved in co-production. The paper suggests that the 5Ws of co-production can offer a useful theoretical lens for analyzing a variety of international co-production cases to inform future policies and practice.