OBJECTIVE: To examine time trends in disparities in low-income children's health insurance coverage and access to care by family immigration status. METHODS: We used data from the National Survey of Children's Health in 2003 to 2011-2012, including 83,612 children aged 0 to 17 years with family incomes <200% of the federal poverty level. We examined 3 immigration status categories: citizen children with nonimmigrant parents; citizen children with immigrant parents; and immigrant children. We used multivariable regression analyses to obtain adjusted trends in health insurance coverage and access to care.. RESULTS: All low-income children experienced gains in health insurance coverage and access to care from 2003 to 2011-2012, regardless of family immigration status. Relative to citizen children with nonimmigrant parents, citizen children with immigrant parents had a 5 percentage point greater increase in health insurance coverage (P = .06), a 9 percentage point greater increase in having a personal doctor or nurse (P < .01), and an 11 percentage point greater increase in having no unmet medical need (P < .01). Immigrant children had significantly lower health insurance coverage than other groups. However, the group had a 14 percentage point greater increase in having a personal doctor or nurse (P < .01) and a 26 percentage point greater increase in having no unmet medical need (P < .01) relative to citizen children with nonimmigrant parents. CONCLUSIONS: Some disparities in access to care related to family immigration status have lessened over time among children in low-income families, although large disparities still exist. Policy efforts are needed to ensure that children of immigrant parents and immigrant children are able to access health insurance and health care.