<p>This article introduces peer-support as a&#xa0;central part of social work focused on self-determination. It begins by examining how self-advocacy is concretely understood in the context of peer-support—at both the individual and organizational levels. Building on this, the article explains why the current state of research on participation in the field of social work must take into account not only the implementation of formal participation rights but also the subjective effectiveness of participation. Against this backdrop, the article introduces the theoretical framework. It draws on a&#xa0;model-based triadic understanding of participation (knowledge, interests, reciprocity), supplemented by powersharing and experiences of participation as perspectives for examining the development of peer-support services in terms of their interactive process dynamics. Powersharing focuses on questions of power, interpretation, and enforcement; experiences of participation reveal how participation can be experienced as connection, effectiveness, and cooperation in the course of interaction. Using two exemplary case vignettes, the article contrasts how participation and inequality take effect differently in a&#xa0;peer context. In the first example, young people’s interests are institutionally framed at an early stage, thereby limiting their opportunities for advocacy and reflection. In the second case study, the concerns of people with disabilities are, following their articulation and recognition, shifted into a&#xa0;process-oriented perspective, making co-constructive follow-up work more likely. The conclusion emphasizes that the application of the triadic participation model in various participation formats should continue to be empirically monitored.</p>