OBJECTIVE: To estimate the effects of Childrens Health Insurance Reauthorization Act (CHIPRA), a policy that provided states the option to extend Medicaid/CHIP eligibility to immigrant children who have not been legal residents for five years or more, on insurance coverage, access, utilization, and health outcomes among immigrant children. DATA SOURCES: Restricted use 2000-2016 National Health Interview Survey (NHIS). STUDY DESIGN: We used a difference-in-differences design that compared changes in CHIPRA expansion states to changes in non-expansion states. DATA COLLECTION: Our sample included immigrant children who were born outside the US, aged 0-18 with family income below 300% of the Federal Poverty Level (FPL). Subgroup analyses were conducted across states that did and did not have a similar state-funded option prior to CHIPRA (state-funded vs. not state-funded), by the length of time in the US (5 years vs. 5-14 years), and global region of birth (Latin American vs. Asian countries). PRINCIPLE FINDINGS: We found that CHIPRA was associated with a significant 6.35 percentage point decrease in uninsured rates (95% CI: -11.25, -1.45) and an 8.1 percentage point increase in public insurance enrollment for immigrant children (95% CI: 1.26, 14.98). However, the effects of CHIPRA became small and statistically not significant 3 years after adoption. Effects on public insurance coverage were significant in states without state-funded programs prior to CHIPRA (15.50 percentage points; 95% CI:8.05, 22.95) and for children born in Asian countries (12.80 percentage points; 95% CI: 1.04, 24.56). We found no significant changes in health care access and utilization, and health outcomes, overall and across subgroups due to CHIPRA. CONCLUSIONS: CHIPRAs eligibility expansion was associated with increases in public insurance coverage for low-income children, especially in states where CHIPRA represented a new source of coverage versus a substitute for state-funded coverage. However, we found evidence of crowd-out in certain subgroups and no effect of CHIPRA on access to care and health. Our results suggest that public coverage may be an important tool for promoting the well-being of immigrant children but other investments are still needed.