Purpose: For preservice teacher candidates (PSTs), receiving feedback on core practices is an important component in supporting the development of their practice. However, coaches are often underprepared to support PSTs on core practices, and feedback can be infrequent or low quality (Anderson and Stillman, 2013; Clarke et al., 2014). Understanding such variation in the content and process for providing feedback to PSTs is important in evaluating and improving feedback effectiveness for amplifying their learning. Design/methodology/approach: The authors studied feedback provided by coaches in response to a video of a sample PST's lesson. The authors examined the extent to which coaches' feedback targeted the core practice of eliciting student thinking and whether this was associated with their assigned PSTs' instructional practices during student teaching. The authors also questioned whether this aspect of coach feedback could be changed in response to professional development. Findings: The results provide preliminary evidence that coaches vary in the extent to which they focus feedback on a particular practice, even when directed to do so. Moreover, when coaches provide focused feedback on a core practice, the PSTs that they coach use the core practice during student teaching. Further, coaches' feedback can be improved through professional development. Originality/value: This study contributes to a limited evidence base examining the association between feedback and PSTs' observed practice. It also establishes that coach feedback can be improved with professional development. The authors discuss these results in the context of documenting and improving teacher preparation.