The term dual, or concurrent, enrollment refers to the broad array of programs available to high school students that allow them to take college-level courses for credit. Dual enrollment creates multiple pathways to college by enabling high school students to take: (1) selected academic courses on college campuses; (2) college-led academic courses at their high school; or, (3) a hybrid of both. In addition, some dual enrollment programs permit students to take post-secondary level career and technical education courses. This study shows Concurrent Enrollment to be highly effective in increasing college graduation for high school students in Colorado. The sample included students across different demographics and academic abilities. Compared to students who did not take college courses while in high school, students who took Concurrent Enrollment courses were more likely to: (1) Attend college within one year following high school graduation, (2) Earn a college degree on time or early, and (3) Have higher workforce earnings after five years. [The Institute of Behavioral Science (IBS) at the University of Colorado Boulder also produced this report.]