Too many students drop out and never earn their high school diploma. For students at risk of dropping out, academic, social, and other supports may help. "Communities In Schools" seeks to organize and provide these supports to at-risk students in the nation's poorest-performing schools, including through "case-managed" services. This report, the first of two from a random assignment evaluation of "Communities In Schools" case management, focuses primarily on the implementation of case management in 28 secondary schools during the 2012-2013 school year. The report also includes interim one-year findings about case management's impact on student outcomes. The report concludes with suggestions for improvement for "Communities In Schools" based mainly on the implementation findings. The next report will present two-year impact findings and more about the implementation of case management in the 2013-2014 school year. Appended to the report are: (1) Statistical Model and Statistical Power; and (2) Sample and Response Analysis.