We estimate that 17% of Medicaid-eligible children in the United States are uninsured, with 27% covered by private insurance. Uninsured children have become a target for state outreach and enrollment efforts. However, the effort may not be a worthwhile use of resources if these children have sufficient access to primary care and are able to enroll in Medicaid should serious health problems arise. This analysis of health status, access to care, and use of preventive and other services suggests otherwise. Although the uninsured Medicaid-eligible children are slightly healthier than their enrolled counterparts, they face reduced access to care and lower rates of service use. After controlling for health status and other characteristics, we find that being uninsured increases the likelihood of being without a usual source of care by eight percentage points, and increases reporting of unmet needs by seven percentage points. Being uninsured also decreases by nine percentage points the proportion of children with any health provider visits, and increases by 12 percentage points the proportion with family out-of-pocket expenses exceeding $500. These findings lend support to the hypothesis that the enrollment process is onerous for some families. Targeted efforts to enroll uninsured Medicaid-eligible children could help in reducing the effect of barriers and reducing differences in access to care.