Temperamental reinforcement sensitivity predicts affective pathology, with BAS sensitivity negatively predicting depression and BIS sensitivity positively predicting both depression and anxiety. Most clinical research on reinforcement sensitivity, however, neglects the role of cognitive mechanisms in mediating these relationships. The current article presents a cognitive coping model of clinical reinforcement sensitivity wherein the relationship between reinforcement sensitivity and affective pathology is mediated by trait preferences for corollary emotion regulation strategies. In Study 1, participants (N = 593) completed measures of reinforcement sensitivity, positive reappraisal, rumination, depression, and anxiety. Exploratory structural equation modeling found that the only model with a good fit included BAS sensitivity predicting reappraisal and BIS sensitivity negatively predicting it. Reappraisal then negatively predicted depression. BIS sensitivity also predicted rumination, which predicted both depression and anxiety. Study 2a confirmed the model developed in Study 1 with an independent sample (N = 513). It then examined longitudinal relationships with a second assessment 6 months later. The relationship from BIS sensitivity to rumination to depression and anxiety remained significant, as did the relationship between reappraisal and depression. Reinforcement sensitivity, however, did not predict reappraisal. In Study 2b, participants (N = 219) were assessed a third time one year later, at the onset of the COVID-19 pandemic. During this stressful time, BAS sensitivity did longitudinally predict reappraisal. These studies highlight the role of emotion regulation in mediating the relationship between reinforcement sensitivity and affective pathology, particularly during times of high stress.