Improving the outcomes of students in developmental or remedial math remains a puzzle in higher education. Concerns with low persistence and completion rates have motivated proponents of reform to reconsider the delivery of developmental math. Lengthening the amount of time in math is thought to be an intervention that improves academic achievement. Does extending time in algebra by a semester help community college students persist and succeed in developmental math and college? The authors investigate this research question using administrative data from four large urban community colleges in California. They first review the literature on increasing time in algebra, drawing largely from studies of middle and high school settings. They then introduce the literature on student persistence decisions in the community college setting and highlight the ways it interacts with developmental math reforms. They next describe the data and the methodological approach--regression discontinuity design--that they used to estimate the effects of enrollment in the extended algebra sequence, focusing on four California community colleges that assign students who earn lower placement scores to an extended two-semester elementary algebra course instead of a typical one-semester course. Results from this study suggest that extending the amount of time in algebra and adding the need for an extra persistence decision is more harmful than beneficial for students at the margin of the cutoff. These students are much less likely to enroll in and complete gatekeeper courses and persist towards credential attainment. The authors conclude with a discussion of how developmental math reforms can increase persistence and success for community college students.