This study investigates one school's approach to increasing high school graduation rates through the use of a school-wide support model. The leadership team at the study site sought to identify and address the primary barriers to graduation at that school. An assistant principal at the study site conducted an independent analysis of student-level data and determined that the primary barrier to graduation was students' inability to pass the state reading assessment. One subgroup in particular who seemed to struggle with the reading requirement were those identified by the Florida Department of Education as being At Risk (AR). AR students are defined by the FLDOE as being individuals who failed both the reading and math assessments in Grade 8 and they carry that designation throughout high school, regardless of performance on subsequent test administrations. In order to improve graduation rates, the leadership team at the study site conceptualized and implemented a Cross-Curricular Reading Program (CCRP) to provide necessary reading interventions in all core classes to assist all students in reaching their academic goals. The purpose of this quantitative research study was to perform a program evaluation on the CCRP at the study site using the regression model difference-in-differences to answer two primary research questions: (1) did the CCRP increase the overall 4-year graduation rate for All Students at the study site and (2) did the CCRP increase the graduation rates of At-Risk and/or Not At-Risk students at the study site? The findings of this study indicate that after controlling for school, teacher, and study characteristics, graduation rates increased for Black At-Risk students. Other findings from the model show increases, but lack statistical significance. [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.]