摘要:Background and Objectives: The Deficit Reduction Act (DRA) of 2005 mandated Medicaid beneficiaries to document citizenship. Using a prospective cohort (n=104,375), we aimed to (1) determine characteristics of affected children, (2) describe effects on health insurance coverage and access to needed health care, and (3) model the causal relationship between this new policy, known determinants of health care access, and receipt of needed health care. Methods: We identified a stratified random sample of children shortly after the DRA was implemented and used state records and surveys to compare three groups: children denied Medicaid for inability to document citizenship, children denied for other reasons, and children accepted for coverage. To combat survey nonresponse, we used Medicaid records to identify differences between responders and nonrespondents and created survey weights to account for these differences. Weighted simple and multivariable logistic regression described the complete, originally identified population. Results: Children denied Medicaid for inability to document citizenship were likely to be US citizens, were medically and socially more vulnerable than their peers, and went on to have gaps in health insurance coverage and unmet health care needs. The DRA led to persistent loss of insurance coverage, which decreased access to needed health care. Having a usual source of care was an effect modifier in this relationship. Conclusions: Our findings demonstrate the negative consequences of the DRA and support the use of automated methods of citizenship verification allowed under the Patient Protection and Affordable Care Act.