Problematic school absenteeism is increasing in most advanced welfare countries. As school success is a well-established factor for improving children's social, mental, and physical development, it represents a fundamental challenge for welfare states. To counteract this development, a variety of different methods and interprofessional collaborations have been developed recently. Despite this, there is little research to date on the roles social workers adopt in mitigating problematic absenteeism. This article presents a study that explored the roles of social workers in a newly developed and rapidly spreading Swedish method, School Social Teams. This study aimed to explore the roles adopted by school socialworkers in these teams and the core components associated with decreased problematic school absenteeism. The study found empirical evidence for three roles and six associated core components: the mediator (creating a communicative space and fostering an understanding of underlying problems); the advocate (establishing a student perspective and advocate at meetings); and the available adult (being available and having endurance). Compared with the existing literature, the mediator and advocate are more theoretically anchored in the literature, whereas the available adult role are related to stronger evidence for mitigating problematic school absenteeism. One conclusion is the importance of deliberate choices of various roles associated with school social work roles as its core components are related to different outcomes.