Many U.S. students arrive on college campus lacking the skills expected for college-level work. As state leaders seek to increase postsecondary enrollment and completion, public colleges have sought to lessen the delays created by remedial course requirements. Tennessee has taken a novel approach by allowing students to complete their remediation requirements in high school. Using both a difference-in-differences and a regression discontinuity design, we evaluate the program's impact on college enrollment and credit accumulation, finding that the program boosted enrollment in college-level math during the first year of college and allowed students to earn a modest 4.5 additional college credits by their second year. We also report the first causal evidence on remediation's impact on students' math skills, finding that the program did not improve students' math achievement, nor boost students' chances of passing college math. Our findings cast doubt on the effectiveness of the current model of remediation--whether in high school or college--in improving students' math skills. They also suggest that the time cost of remediation--whether pre-requisite or co-requisite remediation--is not the primary barrier causing low degree completion for students with weak math preparation.