The phrase "preparing students for college and career" has become so ubiquitous that it has become almost a mantra in educators' discourse in recent years. Whether mentioned in the Common Core State Standards, in the mission statements of high schools, or in political campaigns, improving the college and career readiness of young people is a concept that few can disagree with. Much attention has focused on how to prepare students "academically" for life after high school. But "readiness" also means having the knowledge and skills to make informed choices about careers and postsecondary education options and--once graduated--to successfully navigate both worlds. High schools are expected to teach these skills and knowledge but are rarely given the guidance or tools to do so. With a grant from the Institute of Education Sciences in the U.S. Department of Education, MDRC and its project partner Bloom Associates developed and piloted a program to help schools build or strengthen their college and career exploration programs. Called "Exploring Career and College Options (ECCO)," the program was designed specifically for career academies but can be adapted to fit many educational settings. "Career academies" are schools within schools that enroll up to several hundred students. They are organized by a career theme, such as health sciences or media arts. Besides regular high school courses, career academy students enroll in a sequence of career-technical courses centering on the theme area. Finally, students participate in internships and other experiences in workplaces--which is often called "work-based learning"--to reinforce the connections between what they learn in the classroom and their future careers. An earlier random assignment study of career academies conducted by MDRC demonstrated the effectiveness of the model. Over the years, as the number of career academies grew, the parallel pressure to ensure that all students meet high academic standards inadvertently crowded out time for career exploration activities--the very activities that nonexperimental evidence from the MDRC study suggests may have played an instrumental role in causing the large increases in earnings that career academy participants experienced over the eight-year period following high school graduation. Career academies typically cite a lack of time, skills, and resources as the reason for not offering such activities to all of their students. ECCO is a capacity-building program to help career academies offer opportunities to students to learn about their workplace and postsecondary options through four core components: (1) a series of one-hour in-class lessons; (2) visits to local work sites; (3) visits to college campuses; and (4) a six-week internship offered to all students in the summer before or during their senior year. The curriculum includes guidance for educators on how to arrange and manage students' out-of-school experiences as well as guides for partnering employers. This report summarizes findings from a three-year study of the implementation of the ECCO program. ECCO was launched in 18 career academies in six school districts in three states: (1) California; (2) Florida; and (3) Georgia. The purposes of the study are to document the experiences of these schools in adopting the program and to assess the extent to which, when given support and resources, programs like ECCO can be fully implemented. The study also collected descriptive data to assess the promise of the program to improve student participation in career and college exploration activities and to improve their awareness of postsecondary options. Appended are: (1) Data Sources and Survey Response Analysis; (2) Additional Findings About Implementation; and (3) Additional Analyses of Student Outcomes and Methodological Explanations. Individual chapters contain footnotes. (Contains 38 tables, 12 figures, and 6 boxes.) [This report was written with Marie-Andree Somers.]