Multi-sourcing is gradually becoming the standard operating mode for outsourcing customers. The complex service landscapes of multi-sourcing settings, however, entail significant challenges for customers. They are struggling with managing the various providers and integrating interdependent services. One challenge is to motivate competing outsourcing providers to work together. In this paper, we present five organizational models to establish a service integration and management function in multisourcing. Our findings reveal that service integration and management is differentiated into strategic and operational activities. On the client side, the retained organization is the key organizational unit to perform strategic service integration and management. The organizational entity that performs the operational activities, however, varies with the respective organizational model. Our research is based on a literature review and a qualitative study. With our work, we lay the basis for a better understanding of service integration and management and, thus, more mature multi-sourcing implementations.