Childhood vaccinations are among the most cost-beneficial medical interventions. From the societal perspective, immunizations to prevent pertussis,38,39 measles, mumps, and rubella,40,41 polio,41 varicella,36,42 and hepatitis B26,43 are all cost saving. The present analysis indicates that adolescent hepatitis A vaccination in states with the highest disease rates would reduce societal costs as well. In the 10 states analyzed, projected savings in treatment and work loss costs would be 23% greater than the costs of vaccination, and this strategy would remain dominant unless the price per dose were increased by $5.73, more than 50% above the current federal contract price. Technologies costing the health system $25,000 to $50,000 per YOLS are typically described as cost-effective,44,45 and the $50,000 per YOLS standard is being increasingly applied to economic evaluations of vaccines.43,46 With outcomes discounted to present values, varicella vaccine costs the health system $16,000 per YOLS.36 Similar estimates for hepatitis B vaccine range from $20,61926 to $57,197 per YOLS47 for infants and from $26,00043 to $97,296 per YOLS35 for adolescents. In states with high disease rates, we estimate cost-effectiveness ratios for adolescent hepatitis A vaccination ranging from $5495 (Utah) to $20,569 per YOLS (California), with a population-weighted mean of $13,722 per YOLS for the 10-state region. When disease incidence rates for the United States as a whole were applied to our model, costs exceeded $50,000 per YOLS. However, a 7% reduction in vaccination costs would make a national initiative cost-effective by this standard.