Cardiac rehabilitation improves functional status for patients overall, but debilitating depressive symptoms can undermine efforts. The transience of depressive symptoms makes it difficult for practitioners to identify this modifiable risk factor known to contribute to diminished functional capacity. It is unknown if additional factors may help to explain why some patients with depressive symptoms achieve greater functional capacity (6MWT) than others. We sought to determine: 1) if depressive symptoms at any time in the 12 months following completion of cardiac rehabilitation negatively impact functional status and; 2) if additional factors (exercise, perceived benefits and barriers, self-efficacy, social support, and comorbidity) mediate this relationship. Patients enrolled in a RCT completed measures of depressed mood, perceived benefits and barriers to exercise, exercise self-efficacy, social support, and functional ability (6MWT) at four points of the year following cardiac rehabilitation. Exercise was objectively measured for 12 months using wristwatch heart rate monitors. For those 204 patients (73% men; mean age = 67) reporting an elevated depressed mood score in the 12 months after cardiac rehabilitation, poorer functional status was predicted by their highest depressed mood score when controlling for age, gender, race, and comorbidity (B=-.124, p=.042). Using a partial posterior p-value (p3) and Hierarchical Bayes Confidence intervals (CIHB), significant indirect effects were found for exercise time spent in target heart rate zone (THRZ) (p3=.007, CIHB= -20.69,-2.36), perceived exercise benefits and barriers (p3=.014, CIHB= -16.11,-1.14), and number of comorbidities (p3=.007, CIHB= -14.68,-1.39). Exercise time in THRZ, social support, and self-efficacy did not mediate the relationship (all p3 >.05). Improving the modifiable factors of time in THRZ, and perceived exercise benefits and barriers may be mechanisms by which patients with depressed mood can optimize functional status following cardiac rehabilitation.