Credit recovery is one strategy to deal with high failure rates. The primary goal of credit recovery programs is to give students an opportunity to retake classes that they failed in an effort to get them back on track and keep them in school (Watson & Gemin, 2008). Most recently, as schools across the nation struggle to keep students on track and re-engage students who are off track, online learning has emerged as a promising and increasingly popular strategy for credit recovery: more than half of respondents from a national survey of administrators from 2,500 school districts reported using online learning in their schools for credit recovery, with just over a fifth (22%) reporting "wide use" of online learning for this purpose (Greaves & Hayes, 2008). Despite the growing use of online courses for credit recovery, the evidence base is thin. This paper describes the design and initial implementation of a randomized control trial that was designed to strengthen the evidence base surrounding online courses used for credit recovery. This study is testing: (1) the impact of online Algebra I for credit recovery against the standard face-to-face (f2f) version of the course and (2) the effects of offering expanded credit recovery options with online algebra, relative to business as usual (i.e., the summer programming that schools would offer in the absence of efforts to expand credit recovery). The setting will be Chicago Public Schools (CPS) high schools with freshman Algebra I failure rates of 20% or higher. The target students for this study are first-time freshmen who failed Algebra IB but passed the first semester. The study is first being implemented in summer 2011, and the authors will describe the study design and report on the implementation of the first summer cohort, including challenges and lesson learned from expanding access to credit recovery courses for at-risk students and conducting random assignment "on the spot" as students show up to take summer classes. The paper will also describe methods for measuring student participation and engagement in online courses, including interactions with online teachers, online students and in-class mentors.