This article discusses new evidence on the effectiveness of dual enrollment in increasing college achievement in New York City (NYC). After reviewing existing research on the effectiveness of dual enrollment programs, the authors discuss the results of a recent evaluation of College Now, the dual enrollment program of The City University of New York (CUNY). They find that enrolling in a College Now dual enrollment course reduces time to degree, not only by allowing students to earn college credits before entering college but also by increasing the number of college courses students take once they are enrolled in college. Furthermore, they find that the program also increases students' academic performance as measured by higher college grade point average (GPA). Their study affirms the findings from recent quantitative evaluations of dual enrollment that the programs can indeed help improve post-secondary attainment and reduce time to degree. (Contains 3 tables.)