Peer interactions are a critical component of students' academic success and retention in undergraduate programs. Scholars argue that peer interactions influence students' cognitive development, identity development, self-confidence and self-efficacy, and social and academic integration into the university environment (Pascarella & Terenzini, 1980, 1991, 2005). Research shows that reasonable levels of social interactions along with interactions that are academically-centered support students' persistence in undergraduate study (Bank, Slavings, & Biddle, 1990; Liu & Liu, 2000; Loo & Rolison, 1986). While both social and academic interactions among students shape undergraduate learning experiences, these interactions can differentially influence students' academic success and retention in undergraduate education. This study examined the ways first-year students supported their academic success in undergraduate mathematics-based programs by exploring the types of academic-centered peer interactions (ACPIs) in which students engaged both inside and outside of the classroom setting, and the relationship between participation in ACPIs to retention in undergraduate mathematics-based programs. (Contains 1 table.)