The renewal of IDEA (2004) produced a number of changes in the identification process for children with Specific Learning Disabilities (SLDs). The requirement that students must present a severe discrepancy between IQ and academic performance has been modified to allow for a more flexible problem-solving approach commonly labeled "Response to Intervention." Due to a 2007 policy statement from the State Department of Education, a large, urban school district mandated the development of a Response to Intervention (RTI) system for SLD identification during the 2007-2008 school year. The purpose of the present mixed methods case study was to conduct a site-based examination of the early stages (Year 2) of district-wide RTI implementation. The study took place at three elementary school sites in the targeted district. Results of the study indicated that although the selected school sites implemented all core components of the RTI model, issues surrounding procedural integrity, fidelity, and sustainability remained a threat to potential student benefit. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]