Purpose. To evaluate the impact of transition to managed care from fee for service on asthma service utilization among Maryland Medicaid insured children. Methods. Healthcare claims from 1997-2000 for children with asthma insured by Maryland Medicaid were extracted and analyzed. Results. Between 1997-2000, inhaled corticosteroid use increased as a proportion of all asthma medications. Outpatient asthma visits increased from 4.2% to 5.9% of all outpatient claims as both asthma-related hospitalizations and emergency department visits decreased. Conclusions. Restructuring of Maryland Medicaid for children from fee for service to managed care was associated with improvement in asthma-related healthcare utilization claims.