ABSTRACT Childhood trauma and chronic stress are associated with poor parenting as an adult and subsequent offspring developmental problems. Supportive, cohesive co-parenting (i.e., ways in which parents support/undermine and coordinate with each other in parenting) has the potential to mitigate the impact of childhood trauma and chronic stress on parent adjustment and parenting quality and therefore improve offspring developmental outcomes. Unfortunately, current co-parenting interventions do not address the impact of prior exposure to childhood trauma and chronic stress on co-parenting relationships, limiting the efficacy of such programs among parents impacted by trauma and chronic stress as children. In addition, parents who have experienced trauma and chronic stress as a child may struggle to access services. Thus, a pediatric primary care-based co- parenting program that addresses the impact of childhood exposure to trauma and chronic stress on cooperative caregiving offers a unique opportunity to disrupt the intergenerational impact of childhood trauma and chronic stress and improve developmental outcomes for at risk children. The overall objective of the proposed project is to modify the Family Foundations (FF) Program, an evidence-based primary prevention program designed to enhance co-parenting relationships among cohabitating/married expecting first-time parents, to a primary care-based intervention that mitigates the negative impact of childhood trauma and chronic stress on co-parenting, assessing the feasibility, acceptability, and impact on co-parenting skills of the adapted co-parenting program using pilot tests. The proposed study will use qualitative, intervention development, and implementation science methods to adapt the FF program into a trauma-informed parenting program for caregivers impacted by childhood exposure to trauma and chronic stress. Pilot data collected as part of this study will support future R01 grants focused on implementation of this intervention in a primary care setting and evaluation of the efficacy of this primary care-based trauma informed co-parenting intervention in improving child developmental outcomes among children reared by caregivers endorsing exposure to trauma and chronic stress as children. The proposed application is within scope of the parent NIMHD funded ODEI study (R01MD011598) in addressing the effects of poor co-parenting on child development and innovative in adapting a co-parenting intervention for use in pediatric primary care settings among caregivers impacted by trauma and chronic stress as a child. My long-term research interests center around decreasing racial and ethnic disparities in child developmental problems by developing primary care-based interventions designed to address the impact of exposure to trauma and chronic stress as a child on parenting. To conduct this line of research I require additional training in qualitative methods, intervention development, and implement...