Few digital divorce interventions have undergone rigorous randomized control trial study (RCT) testing of their physical and psychological health effects. This paper describes the Cooperation after Divorce (CAD) intervention including background, target group, design and engagement strategies, intervention development, content, and theoretical cornerstones. The 17-module digital psychoeducational intervention addresses three main content areas: (1) the divorcee themselves, (2) the children, and (3) co-parenting. The content of the modules provided psychoeducation and therapeutic activities focused on the maladaptive interactional patterns between former partners and how to develop new interactional schemas, including a focus on when and how to communicate with the former partner in a way that does not escalate conflict. A randomized controlled trial (N = 778) assessed the effect of CAD in terms of number of sick days. Participants were assessed at 3-, 6- and 12-month post-divorce. Independent samples t test revealed that participants in the intervention group on average reported 5.82 fewer sick days one year post-divorce than did participants in the control condition. The results suggest that digital post-divorce interventions decrease sick days for newly divorce individuals, thereby offering long-term human, family, and public health benefits.