This contribution presents the application of group-analytic epistemology to the development of a professional community of psychologists and psychotherapists working in the private sector, conceived as a space for reflection, cooperation, and shared growth. The experience described illustrates how the principles of Group Analysis can guide the design of a multilayered institutional model grounded in territorial groups, intervision spaces, experiential devices, and a function of institutional supervision and rêverie. After four years of activity, the community includes about eighty professionals distributed across forty territorial sites and represents a concrete example of group-analytic action research within the contemporary professional context. On a theoretical level, the article relates the dynamics of cohesion and incohesion (Hopper) to Esposito’s dialectic of communitas and immunitas, highlighting how Group Analysis can offer an ethical and relational paradigm for rethinking the social function of the psychologist and the processes of belonging within care institutions.