Purpose <p>The transition to motherhood is characterized by increased stress and changes in coping behaviors, yet limited research has examined how different dimensions of parenting stress relate to maternal functioning and media use over time. Guided by the ABC-X model of family stress, this study examined longitudinal associations between parenting stress, maternal depressive symptoms, parenting self-efficacy (PSE), and media coping behaviors.</p> Methods <p>Longitudinal data were collected from 439 mothers across three yearly waves. Parenting stress was measured at Time 1, maternal depression at Times 1 and 2, and parenting efficacy at Times 1 and 3. Health app use was assessed via passive-sensing data, and mothers reported their use of media for emotion regulation at Time 3. Path analyses tested direct associations and moderation by maternal depressive symptoms, controlling for baseline PSE, depressive symptoms, household income, and frequency of cell phone checking at Time 1.</p> Results <p>Parental distress at Time 1 predicted lower PSE and greater media emotion regulation at Time 3. Maternal depressive symptoms further moderated these associations in distinct ways across outcomes. For media emotion regulation, difficult-child stress was associated with lower use only at higher levels of depressive symptoms. For PSE, depressive symptoms weakened the negative association between parent-child dysfunctional interaction and PSE, with stronger associations at lower levels of depression. No consistent associations emerged for health app use.</p> Conclusions <p>Parental distress is a key predictor of maternal functioning, while other stress dimensions show context-dependent associations. Findings highlight the importance of distinguishing stress types and considering maternal emotional context when examining coping and adjustment.</p>