Institutions of higher education increasingly have adopted high-impact practices (HIPs) as a means to increase student retention and engagement. Yet, the growth and assessment of these practices have primarily focused on a student's first and final years, which can contribute to a second-year slump. Administrative data from a small, 4-year liberal arts college are analyzed to investigate when students participate in HIPs and whether this timing affects first and second year retention decisions. Propensity score matching is used to control for selection in which students participate in HIPs. Consistent with previous research, results suggest that HIP participation is a significant predictor of both first and second year retention, though the effect of HIP participation is overestimated without properly controlling for selection bias. Results suggest that strategic incorporation of HIPs in the second year may improve retention outcomes.