PROJECT ABSTRACT. Despite major treatment advancements, inequities pervade care for children diagnosed with congenital heart defects (CHD), the most common congenital defect, with minoritized children (i.e., Black, Latinx) at higher risk of disease complications and death. Parental Participation (PP) is parents’ performing caregiving activities for their hospitalized child, including typical parent activities (e.g., comforting, diapering) and also includes healthcare activities, (e.g., medication administration, decision making). PP is the basis of parents’ essential role, contributes to development of parenting confidence (PC), and leads to positive short and long- term outcomes for children and parents. Further research is needed to understand the mechanisms by which PP influences PC development. Each family’s unique family demographics and social determinants of health (SDOH) can negatively impact PP. SDOH include factors which affect health, including family demographics (family structure, race, ethnicity), SDOH resources (income, insurance, access to transportation), and SDOH processes experienced in the healthcare environment (healthcare discrimination, cultural responsiveness). Children with CHD with low SDOH resources are more likely to have poor access to healthcare and worse outcomes, including a higher risk of death. Despite the demonstrated benefits of PP and PC, there is paucity of research on the impact of family demographics and SDOH on PP and PC in CHD care. A more nuanced understanding of individual factors is desperately needed to discern the ways unique family demographics and SDOH influence PP and PC in the CHD population. This mixed methods study seeks to examine the relationships among family demographics, SDOH, PP, and PC in CHD care among parents of children with CHD (n=110). The aims are to: Aim 1. Examine the influence of family demographics (family structure, race, ethnicity), SDOH resources (income, insurance, access to transportation), SDOH processes in in the healthcare environment (healthcare discrimination, cultural responsiveness of the care environment), and PP on PC using structural equation modeling (SEM) of data obtained via cross-sectional survey. Aim 2. Describe parental perceptions of how family demographics, SDOH resources, SDOH processes and PP affect development of PC in caring for their child with CHD using content analysis of narrative interviews among a group of parents purposively subsampled to encompass diverse levels of PP and PC by race and income level. Aim 3. Construct a comprehensive model of PP and PC, including the influence of SDOH, for racially and ethnically diverse parents using mixed methods integration of data from Aims 1 and 2. Without a more complete understanding of the impact SDOH have on PP and PC in CHD, creation of targeted interventions will fail to meet families’ individualized needs. Results from the proposed study will be foundational to informing explorations of: (1) additio...