Over the last four decades, legislative mandates have increased both educational opportunities and accountability measures for students with identified disabilities in the public school setting. The intertwined relationship between those mandates and the processes used to monitor the progress of a student's individualized goals is complex. This study investigated the current practices of a sample of elementary special education teachers in one county in southeast Pennsylvania. This two-phase study utilized a mixed-methods research design to gather information to help us better understand how teachers are collecting, analyzing, and using data to monitor student progress in selected areas of reading and math, in grades 1-5. In phase-one, a web-based survey was used to gather quantitative information on the processes teachers were employing to collect, analyze, and use student performance information to monitor IEP goals. In phase-two, semi-structured interviews were conducted to provide complementary data on those processes based on teachers' experiences and perspectives. From the research sample, results of the survey and interview indicated that the overall teacher practices were aligned with legislative mandates, and that teachers were utilizing progress monitoring data in many ways. Interview data from one sample district indicated that teachers followed progress monitoring guidelines established by the district, and were provided resources to complete those processes. Results of the study further indicated that teachers most frequently reported using curriculum-based measures (CBM) to fulfill the requirements of this responsibility, and generally agreed that these tools supported their needs. It was also reported, in the context of this study, that additional tools were also necessary to gather relevant student performance information. Interview data gathered from the participating teachers provided insight into some of the additional complexities of the processes including: the competing demands for teachers' time, monitoring students in inclusive instructional settings, using progress monitoring data for purposes of instructional intervention, reporting of progress monitoring data, and using progress monitoring data to collaborate with regular education 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.]