LEARNING FROM ONE URBAN SCHOOL DISTRICT: PROVIDE ESSENTIAL suPPORTs FOR TEACHERS woRK PROFESSIONAL LEARNING COMMUNITIES Rebecca A. Thes sin George Washington University ABSTRACT Numerous districts are implementing Professional Learning Communities(PLCs as a part of reform efforts to improvestudent achievement to meet external accountabiliry mandates Few districts however have considered the essential supports and components that teachers working in PLOsreepiire for these teams to result in instructional improvement. This study reports on the work of one mid-sized urban district that attempted to implement and support PLCs in deneloping essential PLC haracteristics implementing an improvement process, and establishing an instructional goal research based practices shown facilitate improvement This disrict also provided professional development to teachers and administrators in the implementation pracess Findings from this study atirm the research-based practices on which this district implementation plan was based while suggesting that additional school based conditions also needed to be in place: the provision of school based professional on PLCs, (2) a school cilture focused on collaboration, and 3) a readiness by leaders to engage in und communicate expectations for PLC work The study concludes by recommending that districts consider providing differentiated supports and t professional development schools during their first years of PLC among all PLC teams