Undergraduate calculus instruction is a contributor to racialized and gendered trends of STEM persistence and disidentification with mathematics. However, the nature of instruction that promotes equitable learning opportunities for disrupting such negative outcomes and experiences among historically marginalized populations is underexplored. To fill this gap, this paper presents an analysis of 34 undergraduate Black and Latina/o students’ perceptions of discouraging events and alternatives for supportive practices in calculus instruction to build theory of equitable practices. Our findings show how supportive-for-all practices– instructional practices supportive for all students (e.g., creating space for questions and mistakes, extending out-of-class support) – were perceived as necessary yet insufficient to cultivate equitable opportunities for classroom participation and access to content. Black and Latina/o participants’ perceptions of instruction addressed how, without challenging broader influences of racism and patriarchy (e.g., stereotypes of mathematical ability), historically marginalized students have limited access to learning opportunities afforded by supportive-for-all practices. The present study, therefore, demonstrates how equitable calculus instruction requires race- and gender-conscious enactment of supportive practices, which challenges colorblind and gender-neutral assumptions of uniformity in students’ experiences of instruction that leave structural forms of exclusion unchecked. We conclude with implications for practice and research.