Academic behaviors such as attendance are highly associated with academic outcomes. High schools are also increasingly turning to online courses to educate their most marginalized students. In this study, I explored the extent to which enrollment in an online course improved engagement and allowed students to make course progress online outside the traditional school day by examining within-student changes in academic behaviors. Students completed their online course in fewer class periods than required to complete a comparable course in a traditional, face-to-face instructional setting. At the same time, students attended, on average, three additional days of school when enrolled in an online course as when enrolled in solely face-to-face courses, indicating a potentially positive spillover effect. Results have implications for practitioners and policy makers interested in online learning and understanding what programs might be most effective in reengaging students at risk of course failure or dropping out of high school.