The present study sought to determine the extent to which participation in a post-secondary honors program affected academic achievement. Archival data were collected on three cohorts of high-achieving students at a large public university. Propensity scores were calculated on factors predicting participation in honors and used as the covariate. The Johnson-Neyman technique was used to determine the values of the covariate on which the groups differed. The effect of participating in honors was greater for smaller propensity scores. The findings offer a positive outcome associated with participation for students at the lower end of the propensity score continuum, providing evidence to conclude that such programs are beneficial to a subset of high-achieving students.