Multiple models of Integrated Care (IC) have been implemented in German mental health services in the last decade in order to improve cross-sectoral, interdisciplinary cooperation. This study investigates an IC network model providing home treatment, case management and a 24/7 hotline. The aim of the study was to explore how health professionals working in this service model perceive both cooperation within their facilities and with external stakeholders. 5 focus groups with 39 health professionals working in an IC mental health network were conducted and analyzed with qualitative content analysis. Focus groups participants reported on excellent cooperation within their facilities. The cooperation with external stakeholders, i. e. physicians, psychotherapists and psychiatric clinics, leaves room for improvement. Until now little consideration has been given to the perspectives of health professionals. Cooperation within IC mental health networks seems to be effective. Cooperation with stakeholders outside the networks needs to be enhanced.