Business informatics and medical informatics adopt and adapt methods and knowledge from computer science and further develop appropriate methods for the particular needs in their application domains. A panel discussion at the 2018 conference of the German Society for Medical Informatics, Biometry and Epidemiology (GMDS) analyzed the relationship between business informatics, medical informatics and computer science. Five questions guided the discussion:The analysis made clear that business informatics, medical informatics and computer science would gain profit from a more systematic mutual exchange. The “Learning Healthcare System” could provide a useful framework.