Background: In 2016 The Belgian government launched a Reform program to optimize and integrate care for Mentally Ill Offenders MIO. Collaboration networks get the ‘mandate’ to implement the program, adapted to locoregional contexts. This paper aims to make a plan analysis of the government reform program and tries to analyze the characteristics of the mandate.Methods: Qualitative data were collected using document analysis and semi structured interviews with policy delegates cabinet and administration and regional healthcare- and justice coordinators. Data were analyzed using a continuous comparative method, including researcher triangulation.Results: The current policy framework sets a number of guiding principles to reorganize the field and care for MIO. Key principles are the focus on integration of care of services form different sectors and organizations, reintegration of MIO into society, developing smooth patient trajectories for MIO and emptying the prisons with MIO by means of introducing new types of facilities. The responsibility to implement this is mandated to policy implementation networks per regional Court of Appeal region.The Master Plan holds no detailed rules or procedures to guide the collaboration. The plan incorporates previously established locoregional steering groups and strengthens the role of steering group coordinators to enhance collaboration. These latter are the linking-pin between locoregional activity and the policymakers. The locoregional coordinators are supervised by a national coordinator. These coordinators have to facilitate the dialogue between organizations to realize the guiding principles, facilitate a common understanding of integrated care and facilitate intersectoral patient trajectories of different types of MIO’s.Discussion: The strategy of the Reform plan is in line with recommendations in literature to tackle wicked problems. The reform plan aims at developing common goals through locoregional dialogue of intersectoral partners. It tries to guide this process by ...