Developmental education (dev-ed) aims to help students acquire knowledge and skills necessary to succeed in college-level coursework. The traditional prerequisite approach to postsecondary dev-ed--where students take remedial courses that do not count toward a credential--appears to stymie progress toward a degree. At community colleges across the country, most students require remediation in math, creating a barrier to college-level credits under the traditional approach. Corequisite coursework is a structural reform that places students directly into a college-level course in the same term they receive dev-ed support. Using administrative data from Texas community colleges and a regression discontinuity design, we examine whether corequisite math improves student success compared with traditional prerequisite dev-ed. We find that corequisite math quickly improves student completion of math requirements without any obvious drawbacks, but students in corequisite math were not substantially closer to degree completion than their peers in traditional dev-ed after three years.