Chapter 7 of Edited Volume: Pouezevara, S. R. (Ed.) (2018). Cultivating dynamic educators: Case studies in teacher behavior change in Africa and Asia. (RTI Press Publication No. BK-0022-1809). Research Triangle Park, NC: RTI Press. DOI: 10.3768/rtipress.2018.bk.0022.1809 This case study explores the methods and implementation considerations of peer-learning approaches to changing teaching practice in the Indonesian context, where cluster-based training is deeply embedded in the education system. These clusters were leveraged by USAID/PRIORITAS to disseminate professional development through a structured lesson-study approach. To understand more about how teachers were learning to improve their practice through peer mentoring, data were collected through interviews and school visits in August 2016. The main purpose of the case study was to understand the scope and implementation considerations of school-based and peer-to-peer approaches to teacher behavior change, with particular focus on improving reading instruction. We particularly have tried to uncover the implementation factors that influenced the possibility of success of peer mentoring in Indonesia under USAID/PRIORITAS, including issues of intrinsic and extrinsic motivation, readiness for self-directed learning, and the relative importance of the foundation laid by the preexisting school- cluster structure described in the Methodology section.