This study examines changes in coparenting quality during the initial stage of the COVID-19 pandemic on long-term parent, child, and family well-being. Although there is clear evidence that the COVID-19 pandemic negatively impacted families, less is known about family resilience factors that could mitigate this impact. Understanding whether positive coparenting quality is a protective factor during crises is important for promoting parent, child, and family well-being. The study collected data from 150 parents who participated in a transition-to-parenthood intervention trial 10 years prior. Hierarchical linear modeling was used to examine the association between changes in coparenting quality from before the pandemic (Time 1) to the early stage of the pandemic (Time 2) with parent, child, and family adjustment 19 months later (Time 3). Moderation effects were also explored. Over half of parents reported a decline in coparenting relationship quality between Time 1 and Time 2 while about one third reported an improvement. A more positive change in coparenting was associated with better parent and family adjustment at Time 3. Moderation analyses showed that positive changes in coparenting were associated with fewer internalizing symptoms for female children and, for families with younger children, increased positive and decreased negative parenting behaviors. These findings support the idea that positive coparenting can serve as a resilience factor during times of crisis. Practitioners working with families in crisis should consider incorporating coparenting interventions and strategies. (PsycInfo Database Record (c) 2024 APA, all rights reserved).