Abstract The notion of practice-based models for mathematical knowledge for teaching has played a pivotal role in the conception of teacher knowledge. In this work, teachers’ knowledge of mathematics that is outside the scope of what is being taught (nonlocal mathematics) is considered more explicitly. Drawing on a cognitive model for the development of mathematical knowledge for teaching, this paper explores the implications for the underlying theory being applied to (nonlocal) knowledge outside the scope what is being taught as being influential for the teaching of (local) mathematics. The work provides a unique perspective on the role of advanced mathematics with respect to secondary teaching. Considerations for mathematics teacher education are discussed.