Background/Context The literature shows that one constant in coaching is the high degree of variation in coach roles and contexts, suggesting that understanding coaching practice requires that we also understand the role structures and organizational conditions that shape coaches’ work. Research on both instructional coaching and instructional change is increasingly attending to the organizational and social factors that shape, facilitate, and constrain the web of interactions that coaching work comprises. Past research points to the complex systems and social networks that shape critical elements of coaching practice, emphasizing the interdependency of organizational processes and the critical importance of considering not only the outcomes of implementation, but also the contextual factors that shape them. Purpose/Objective/Research Question/Focus of Study Given that multilayered social, technical, and organizational factors shape the practice and impact of instructional coaching, understanding the combinations of factors that are most consequential is key for both policy implementation and instructional coaching research. Consequently, understanding coaching requires attending to specific practices, the structural contexts in which those practices are embedded, and varied implementation processes across system levels and diverse school districts. Therefore, we built this study on the foundational idea that coaching work inherently and continuously interacts with the complex systems in which it takes place and that understanding and analyzing coaching requires attending to the organizational and social structures that shape it. Accordingly, this article focuses on the following research question: What contextual conditions facilitate and constrain coaching, and why? Research Design To understand the interactions between coaching work and these many social and technical factors, we investigated how a group of coaches implemented a mathematics coaching model, focusing specifically on the relationship between coaching contexts and coaching practice. Our case-focused, mixed-methods approach, which included both qualitative comparative analysis (QCA) and case-study methods, allowed us to explore the interrelationships between coaching and the system conditions that shape, enable, and constrain instructional change. Conclusions/Recommendations Our findings support the argument that coaching cannot be extricated from the surrounding system factors that shape it. On the contrary, we found that supports for and barriers to robust coaching practice are context-specific phenomena, suggesting that any coaching intervention ought to be tailored to its specific organizational location. Accordingly, we argue that different combinations of contributing factors can affect coaching in different ways, thereby contributing to the theory that a nested-systems perspective on instructional coaching is key to understanding its effects.