Community college students face special challenges that can impede their academic progress, resulting in lower grades and persistence than students in selective four-year colleges. Kingsborough Community College in Brooklyn, New York, successfully addresses these challenges with learning communities: small cohorts of students in a blocked program of study, which includes developmental or basic English, a one-credit student skills course, and a social or behavioral science course. This research analyzes the short-term effects of the model by comparing a sample of 267 students enrolled in four learning community and four regular sections of sociology and psychology classes. The results demonstrate a high positive impact for learning communities on student success as measured by grades and course completion rates, with higher levels of engagement and lower rates of absences in learning community sections as the key causal mechanisms. That is, statistically significant correlations between mode of delivery and grades are reduced when controlling for absences, elaborating on and perhaps explaining the well-established relationship between learning communities and short-term student success.