Background or Context: Culturally responsive instruction (CRI) has garnered significant attention in local and state policy in recent years amid politicization of what is taught in schools, and the scholarly field is increasingly focused on how to develop culturally responsive "schools" and "systems," not just culturally responsive teachers. As the field considers how to support teachers to take up culturally responsive practices, there is a need to understand practicing teachers' current understandings and perceptions of CRI and their school and sociopolitical environments. Purpose, Objective, Research Question, or Focus of Study: I examine how practicing teachers understand and describe CRI and their perceptions of the aspects of their school and social contexts that may support CRI. Specifically, I ask: (1) What are practicing teachers' conceptions of CRI? (2) What role do practicing teachers perceive their schools and the broader sociopolitical environment to have in supporting or hindering their efforts to engage in CRI, and how are these perspectives related to their conceptions of CRI? Research Design: This qualitative interview study draws on 22 interviews with teachers across five districts engaging in professional learning initiatives. Through coding, memoing, and use of analytic matrices, I conducted thematic analysis to understand teachers' conceptions of and beliefs related to CRI, as well their perceptions of the ways their school and the broader social context influence their efforts to engage in CRI. Conclusions or Recommendations: I find that teachers' conceptions of CRI and perceptions of their school and sociopolitical contexts were mutually reinforcing: teachers largely called attention to aspects of their contexts that aligned with and reinforced their conceptions of CRI. Teachers with more robust conceptions of CRI drew attention to dynamic school characteristics like a culture of critical reflection as helpful in promoting CRI, whereas teachers with less developed conceptions of CRI emphasized a set of static school factors that reflected a superficial treatment of cultural responsiveness. This study speaks to the need to center teachers' meaning-making when supporting their development of CRI and to move toward more ecological perspectives for understanding and developing culturally responsive and justice-oriented systems.