This article contributes a deeper understanding of teachers' experiences with and beliefs about teaching mathematics for social justice in urban schools. In-depth, phenomenological interviews were conducted with a national sample of 15 secondary mathematics teachers from eight cities across the United States. Findings identify five overarching commitments of social justice mathematics teachers, the barriers they face, and what they envision for the future of urban mathematics education. Drawing on critical pedagogical theory, this study uncovers how social justice mathematics teachers have on-the-ground experiences and perspectives that can help us build upon Freire's notion of education for liberation.