This study examined the effects of stimulus-feedback co-occurrence on rule-based and information-integration category learning. Rule-based categories are those for which a verbalizable rule is optimal. Information-integration categories are those for which the optimal rule is non-verbalizable. Participants performed a rule-based or an information-integration task where the stimulus co-occurred with the feedback (Stimulus Present) or was removed prior to feedback presentation (Stimulus Absent). Previous research examining the neural substrates of rule-based and information-integration category learning suggests that stimulus-feedback co-occurrence should support rule-based learning, but should harm information-integration learning because it will increase the prevalence of rule use. This prediction was confirmed in the current study. Implications for theories of category learning are discussed.