PROJECT SUMMARY/ABSTRACT Food insecurity (FI) affects almost 18 million children across the United States, placing them at increased risk of adverse health outcomes including poor physical and mental health, behavioral problems, and developmental delay. Children experiencing FI are also less likely to access preventive care and experience increased rates of delayed medical care due to cost and increased emergency department (ED) utilization. FI disproportionately impacts Black and Hispanic children and children from immigrant families and can therefore exacerbate existing disparities in these children's health and healthcare utilization. Childhood FI therefore represents an important priority for health systems, payers, and policymakers seeking to increase access to care, improve outcomes, and reduce avoidable healthcare utilization and costs. Government nutrition benefit programs, such as WIC and SNAP, are key sources of nutritional support for families with FI. Participation in these programs has proven health benefits, including decreased rates of preterm birth and low birthweight among infants, and improved diet quality and reduced FI among children. However, only 50% of eligible women and children currently receive WIC, and only 75-85% of eligible households receive SNAP. Healthcare providers and health systems could therefore mitigate the negative health impacts of childhood FI by identifying families who are eligible for, but not enrolled in, WIC or SNAP and providing them with enrollment assistance. Enrollment assistance interventions have the potential to both enhance health and social service integration and generate cross-sector cost savings for payers and health systems. In order to inform the design and implementation of novel, effective enrollment assistance interventions, there is a critical need to (1) characterize the impact of WIC and SNAP participation on children's overall health and access to healthcare, (2) characterize healthcare utilization patterns and healthcare expenditures for children who are eligible for, but not receiving, WIC and SNAP benefits, in order to determine where enrollment interventions should focus and estimate potential cost savings associated with increasing enrollment, and (3) develop family- centered strategies for providing WIC and SNAP enrollment assistance in healthcare settings. The specific aims of this application are: (1a) to examine associations between WIC and SNAP participation and caregiver- reported child health and access to care, (1b) to examine the association between WIC and SNAP participation and healthcare utilization and expenditures, and (2) to explore food insecure families' perceived determinants of government benefits enrollment and their revealed preferences for health-system based benefits enrollment support.