This descriptive case study explored literacy preservice teachers' (PTs) learning for the use of practice-based research and the impact of research experiences on their literacy teaching. This project spanned two courses and two contexts: a learning and development course focused on PTs' stance as inquirers, activists, and practice-based researchers, with work in a field placement classroom, and a reading methods course, focused on literacy teaching through inquiry and activism, with a mediated literacy mentoring experience. The researcher employed framings of communities of practice and transformative activism in analyzing PTs' identity development as researchers, identifying resources and design features that supported PTs' learning, and understanding connections between PTs' stances as inquirers and use of inquiry as literacy curriculum. Findings indicate the ongoing identity development PTs experienced as they used practice-based research to envision and enact transformative possibilities in literacy teaching.