Abstract Immigrant children face unique hardships in accessing Medicaid and the Children’s Health Insurance Program (CHIP) because states can exclude them from eligibility during their first five years of legal residency (a rule known as the “five-year bar”). The Children’s Health Insurance Program Reauthorization Act of 2009 (CHIPRA) gave states the option to eliminate the five-year bar restriction. However, little is known about the effect of CHIPRA on the targeted population’s health, health care access and utilization. Furthermore, fear that program participation will lead to immigration enforcement may depress program take-up. Such fears are likely pronounced in families with undocumented immigrants. Utilizing quasi-experimental difference-in-differences methods that leverage state-by-year variation in the policy environment, I will examine the impacts of CHIPRA’s eligibility expansion to immigrant children that have been in the US for less than five years. Using nationally representative data from 1997- 2018 National Health Interview Survey that includes state identifiers, I will study effects of CHIPRA on health insurance coverage, health care access and utilization of immigration children under the five-year bar. Next, I will evaluate the effect of CHIPRA on the physical and mental health of immigrant children under the five-year bar. As a sub-aim, I will determine if effects of CHIPRA expansion varied by the presence of pre-existing insurance programs covering low-income immigrant children under the five-year bar. Further, I will examine if insurance take-up varied by household immigration status. This project is centered on an AHRQ priority population—children in low-income and minority families. The proposed project is directly in line with AHRQ’s mission to evaluate strategies that make health care more accessible, equitable and affordable. Results will fill an important gap in the literature by determining the direct effects of expanding public insurance to recently arrived immigrant children and by describing how household immigration status impacts the take-up of public benefits. The results will help state and federal policymakers make evidence based decisions that weigh program benefits against program costs.