This article relates a study on the organization of the mental health services in the primary care network of the city of Campinas (SP), beginning with the implantation of the management model called Matrix Support. This organizational arrangement is aimed at integrating primary and mental care by redirecting indiscriminate actions to the logic of co-responsibility in order to produce major effectiveness. Focal groups composed by mental health professionals from reference teams and managers were created. From the perspective of a hermeneutic-critical approach, we sought interrelating narrative argumentations with the construction of meanings. The incorporation of the mental health actions in the reference teams, as well as diversification of therapeutic measures was observed. We also evaluated the need to improve risk evaluation and to create permanent spaces for analyzing the potential of the Matrix Support to change hegemonic practices. This article aims to contribute to the discussions about changes in the policies and care services in the field of mental health.