Coaches make hundreds, if not thousands, of decisions that affect the daily work of teaching and learning. These decisions are not arbitrary; they are guided by the mental models coaches hold. Mental models are comprised of assumptions, beliefs, and generalizations, and they shape how people see the world and act in it. Coaches' mental models are powerful factors in determining how they see and understand their clients' classrooms, the school context and culture, and the work that needs to be done. This is one reason that different coaches often respond differently to the same situation. It is important for coaches to analyze their mental model, understand how it influences their work, and ultimately learn to expand it to best meet clients' diverse needs and contexts. This article explores three predominant mental models of coaches and proposes how coaches can overcome their limitations.