In 2002, the No Child Left Behind (NCLB) legislation greatly enhanced the school accountability movement in the US and resulted in pervasive influence, mandating student achievement outcomes in low-income school communities. Of particular challenge has been the NCLB requirement to advance student achievement each year according to designated achievement goals with 100 percent of all students achieving proficiency by the year 2014. For those schools and districts in California not making these goals, NCLB designates them as underperforming and places them in a category requiring considerable oversight termed program improvement (PI). More and more schools are being identified as underperforming or as Program Improvement (PI) institutions according to NCLB; yet some schools in this category make the achievement progress necessary to "Exit PI" and stand apart in overcoming considerable obstacles. The purpose of this multi-case qualitative study was to explore a sample of principals' perceptions of the strategies and practices they adopted that resulted in meeting NCLB achievement goals and the "exiting" of Program Improvement (PI). The study focused on how principals interacted with and overcame the challenges associated with negative school cultural perceptions in a school community that was designated PI. The study also sought to identify the common strategies and practices that resulted in improving student achievement that can be replicated in other schools. Three major findings in this study highlight the approaches used by principals in order to exit PI. The first of these findings identified the importance of addressing school cultural issues. This was a multi-year process driven by ongoing efforts at collaboration, data-analysis, teacher training, and ongoing teacher feedback. The second finding highlighted the importance of instructional leadership. This leadership was provided through ongoing classroom observations, clarifying performance expectations for teachers, and through modeling and coaching to assist teachers in adopting effective instructional practices. The third finding underlined the importance of primarily focusing on established state curricular standards instead of relying exclusively on the adopted curriculum. This focus was brought about as teachers collaborated and reviewed student achievement data and then considered how to best plan instruction for the state assessment. [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.]