This article examines how deaf students and interpreters experience positioning within mainstream educational settings, with a focus on environments where a critical mass—defined as multiple deaf students and interpreters—is present. Drawing on interviews with 41 formerly mainstreamed deaf individuals and interpreters, the study explores how critical mass influences engagement, participation, and perceived membership in the school community. Findings suggest that critical mass enhances access to Deaf Community Cultural Wealth (DCCW) and fosters collaborative positioning. These environments strengthen support systems for both deaf students and interpreters. These environments also promote professional development among interpreters and contribute to more inclusive school climates. The study is framed by positioning theory and DCCW, offering insights into how systemic and interpersonal dynamics shape educational experiences. Implications are discussed for both deaf education and interpreter education communities.