Co-teaching is recognized as an evidence-based approach for advancing inclusive education by integrating the expertise of general and special educators to enhance differentiation, progress monitoring, and access to grade-level curriculum. When implemented with fidelity, co-teaching promotes inclusive learning environments and social outcomes for students with and without disabilities; evidence regarding academic achievement gains is more mixed and context-dependent, with outcomes varying by implementation quality, model used, and student population (King-Sears et al., 2021). However, it often underperforms when treated as a placement rather than as a collaborative instructional system that requires shared responsibility and planning. Research studies identify common planning time as a critical factor for effective implementation. Without protected co-planning opportunities, instruction frequently defaults to less effective models, such as oneteach, one-assist. Such models limit instructional parity and reinforce hierarchical roles (Friend et al., 2010; Scruggs et al., 2007). Persistent barriers, including scheduling constraints and competing demands, continue to undermine the quality of co-teaching (King-Sears et al., 2021; McLeskey et al., 2022). Our paper positions protected co-planning time as an equity imperative essential to realizing the full potential of inclusive education.