Barriers for social inclusion of vulnerable groups respond both to the socioeconomic context of each territory and to the orientation and institutional design of public policies. In this regard, the collaboration between social services and employment services is crucial to improve social inclusion. However, the difficulty of coordination between systems is manifest. This article proposes keys to analyze the institutional relationship of services oriented to the socio-labor incorporation of excluded people. The results arise from a comparative analysis of the institutional models of social services and employment services in five autonomous communities of Spain. On that basis, the keys and challenges of services integration are identified.