Abstract Until the end of the twentieth century, child custody arrangements after separation typically continued the gendered pre-separation parenting division, with mothers taking up childcare and fathers paying child support. Recently, there has been a significant rise in co-parenting after separation, reflecting the trend towards more socio-economic, work- and childcare-related gender equality during the relationship. However, it remains unclear to what extent the organization of the pre-separation household dominates over important changes in the lives and labor force participation of parents after separation in choosing to co-parent. This study uses longitudinal Belgian register data to consider the effect of post-separation dynamics in parents’ life course and labor force participation in deciding to co-parent. While certain pre-separation characteristics remain predictive of co-parenting, our results suggest a societal trend towards co-parenting as the parenting norm. Increased time in paid work positively affects co-parenting probabilities, but we find no effect of a post-separation income increase, even though this would imply greater bargaining power to obtain sole custody. As such, the investigated post-separation changes seem to be an indication of parents moving towards supporting and attempting to gain gender equal parenting after separation.