This dissertation addresses the dynamic interaction between policies aimed at urban education reform and teachers' role in advancing policy objectives. It examines teacher agency in the context of proposed community and school change by focusing on teacher involvement with policy implementation. It investigates teacher views of their individual and collective efficacy as instructors in a school of an economically distressed community as well as the extent to which teachers view themselves as agents of change to present a new heuristic or model for understanding teachers' roles in non-traditional approaches to urban school reform, which I argue can be used to inform practitioners, teacher educators, and policymakers tackling the problem of persistent underperformance in urban schools. Relying on case study methodologies, this research aims to provide an understanding of the complexities involved in reforming and "transforming" urban schools labeled as "chronic failures" particularly as it concerns teachers' ability to interpret, adopt, and appropriate an urban renewal project in a Northeastern city of the United States, one of the top five poorest in the nation. For example, using elementary and middle school teachers as the unit of analysis, the heuristic detailed in this study supplies a new conception for identifying a range of teacher perspectives revealing that successful implementation of such an ambitious goal as community and school transformation has implications for teachers' a) policy knowledge and active participation in implementation b) perceived instructional efficacy both at the individual and collective levels and instructional approach, as well as c) the ways in which teachers position themselves toward students and their families and the school's broader community. Looking closely into the complex ways in which teachers viewed the content of a particular reform policy, their capacity to instruct in a critical manner prescribed by the policy, and the context of their practice, four conceptualizations of teacher agency emerged. In identifying a range of perceptions from absence to toward full awareness, this study expands notions of teacher agency and educational change in one significant way: it highlights the multifaceted and at times fluid nature of teacher agency which may be understood as more than simply high or low, but also limited and vacillating. As such, it complicates current understandings of teachers as either having agency or not by focusing on teacher positioning of themselves as change agents. The results of this study expose a potentially important point of leverage in undertaking the problem of persistent underperformance in urban schools chronically labeled as failing by directing practitioners, teacher educators, and policymakers toward specific areas of focus that will impact the development of highly agentic teachers. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]