Little is known about the everyday experiences of individuals transitioning from acute to outpatient psychiatric care, an important period of risk for mood symptom relapse. This study used ecological momentary assessment (EMA) to examine whether specific daily experiences were related to momentary affective states following discharge from a partial hospitalization program (PHP). A sample of 114 adults (Mage = 36 years old, 52% female, 83% White) completed four brief EMA surveys every day for 2 weeks assessing intensity/type of stressful events and social contact, as well as positive/negative affect (PA/NA). Half of participants reported therapeutic skills use. Stress severity ratings prospectively predicted increased NA. NA predicted spending less time with close relationships. However, interacting with close relationships predicted increased positive affect (PA). Finally, PA predicted spending time with more people. The use of two skills (behavioral activation and interpersonal effectiveness) was concurrently, but not prospectively, associated with improved affect. Examining daily experiences of individuals discharging from partial hospitalization provides important information about factors that may influence affective states during the transition from acute to outpatient care. Findings from this study can be used to help prepare patients for discharge and develop interventions for the post-acute period.