The Communities In Schools (CIS) Model of Integrated Student Supports aims to reduce dropout rates by providing students with integrated and tiered support services based on their levels of need. The model includes preventive services that are available to all students (Level 1 services) as well as intensive, targeted, and sustained services provided through case management (Level 2 services) for the 5 percent to 10 percent of students who display significant risk factors for dropping out, such as poor academic performance, high absentee rates, or behavioral problems. This study, which is based on a quasi-experimental research design, examines the CIS model's effect on students' outcomes in elementary schools, middle schools, and high schools. The sample for this study includes 53 CIS schools in Texas and North Carolina (14 high schools, 15 middle schools, and 24 elementary schools) that started implementing the CIS model between 2005 and 2008. The study compares these CIS schools with 78 matched comparison schools (18 high schools, 24 middle schools, and 36 elementary schools). For the high schools, the main finding is that on-time graduation rates increased--and dropout rates decreased--in the study schools after the CIS model was launched. Graduation and dropout rates also improved in the comparison schools, so it is unclear whether the CIS model was "more" effective than the strategies used by the comparison schools. The findings do suggest that the CIS model may be at least as effective as these other approaches. The following are appended: (1) The Statistical Model and Baseline Trend Estimates; (2) The Selection of Schools Implementing the Communities In Schools Model; (3) The Selection of Comparison Schools; (4) Standard Deviations; (5) Sensitivity Analyses; (6) Findings for Schools in Texas; and (7) Statistical Power and Minimum Detectable Effects. [For the executive summary, see ED574039.]