This study examines academic outcomes for university students engaged in a supplemental peer learning program in a selective institution. Using a matched sample of 1266 students, half enrolled in the supplemental program and half not enrolled, we find that participating students on average earned higher grades in linked courses. Using a subsample of students in a chemistry course sequence, we find program participants were more likely to remain in the sequence than non-participants, and that the impact was greater for students with lower levels of preparation.