Signed into Law on January 8, 2002, the 1,180 page No Child Left Behind Act (NCLB) shifted the course of public education in America. For the first time accountability was firmly placed at the center of school operations by requiring a systematic approach to achieving reform and improving all areas of school life (Wanker & Christie, 2005). As plans were quickly implemented to meet deadlines, strong opposition was voiced to the unfair way the primary requirement of Adequate Yearly Progress (AYP), was to be measured. Using a status model, success was measured by using a snapshot of educational progress compared to a predetermined goal or dissimilar group of students. Credit could not be earned for progress of non-proficient students. In response, educational researchers have introduced growth modeling as a way to give credit to schools and districts when students make progress on standardized tests yet remain below the proficient mark (Andrejki, 2004; Callender, 2004; Hull, 2008). In December 2005, the United States Department of Education opened a pilot project allowing states to apply to use growth modeling in NCLB accountability plans (United States Department of Education, 2005). This dissertation research examines the implementation of a growth model program in three states: Delaware, Iowa and North Carolina. These states were chosen for their differences on a multitude of factors to provide a rich description of growth model implementation. Using qualitative research techniques the decisions, implementation, data use, and statistical considerations were examined. The findings reveal substantial information on the growth model implementation process with three significant themes emerging from the data. Stakeholders played a significant role in each step of the process at varying degrees in each state. The involvement of stakeholders was found to be important when making decisions and also to garner support for each program. Reporting results to stakeholders was a central piece of each state plan. Lastly, in all three states policy makers and technology efforts saw the benefit of working together to ensure that business rules were possible to implement and the results understandable. The research contributes a rich description of real-world growth model implementation experiences in state level NCLB accountability plans to three important bodies of academic literature: No Child Left Behind, Growth Modeling, and Policy Implementation. Additionally, the discoveries start a guide for educational leaders to evaluate when deciding to add the statistical procedures into NCLB accountability plans. [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.]