To describe healthcare use over time of children with a history of neonatal abstinence syndrome (NAS) compared with children without NAS. In this retrospective, longitudinal cohort study, data were obtained from MarketScan Commercial Claims and Encounters database from 2005 to 2014. Children with and without NAS based on International Classification of Diseases, Ninth Revision diagnostic codes were followed until 8 years or disenrollment (mean: 35 months). Numbers of claims for inpatient, outpatient, and emergency department encounters; prescription drugs; and costs associated with these encounters were evaluated. Children with NAS had a significantly greater number of claims per year from age 1 to 8 for inpatient hospitalizations (adjusted mean ratio 3.20; 95% CI 1.74-5.90), outpatient encounters (1.23; 1.08-1.41), and emergency department visits (1.46; 1.25-1.70) after we adjusted for confounders. Subsequently, adjusted mean annualized costs were nearly double for all healthcare services in children with NAS (1.86; 1.34-2.60) and >4 times as high as for inpatient hospitalizations (4.34; 2.03-9.30) compared with children without NAS. Children with a diagnosis of NAS have significantly greater rates of healthcare use through age 8 years compared with children without NAS. These findings suggest that children affected by NAS have medical disparities that linger well beyond early infancy.