Teaching is a challenging profession. It requires juggling multiple roles in and out of the classroom while also being a mentor, an administrator, and a researcher. Therefore, as teachers gain experiences and establish routines, it is natural that some fall into a pattern of relying on the same teaching strategies and activities with little change. However, others continue to create new class activities or refine old ones as well as helping colleagues and contributing to improving programs. These teachers are often exceptional, and in many cases considered experts. Researchers have unveiled characteristics of expertise in teaching as well as its developmental processes (e.g., Asaba, 2019; Christiansen et al., 2018; Tsui, 2003). However, what these findings mean for educators have not been fully explored and discussed. The purpose of this presentation is to explore what previous studies of expertise in L2 teaching suggest for teaching and learning in L2 communities. The presenter first introduces previous literature and key concepts related to expertise in teaching, including teacher knowledge and a model of expertise known as progressive problem solving (Bereiter & Scardamalia, 1993). Then, the presenter will discuss implications that these studies have for teachers, administrators, and researchers in L2 teaching contexts.