Improvements in the healthfulness of packaged foods and beverages through reformulation could help reduce the prevalence of obesity among children and adolescents through improved diet quality. This study assessed changes in calories and four nutrients (saturated fat, total sugars, sodium, and dietary fiber) from 2012 through 2014 for packaged products frequently consumed by children and adolescents, simulated effects of potential improvements in 12 frequently consumed product categories based on actual purchasing patterns, and compared differences in prices of healthier versus less healthy products. Analysis of trends showed limited evidence that healthfulness of foods improved over the years examined. Simulation results showed minimal changes for calories and sodium, but daily intake of saturated fat could decrease by 4%, sugar consumption could decrease by 5%, and dietary fiber consumption could increase by 11% if products were reformulated to meet an existing healthfulness standard. Using a higher standard, caloric intake could decline by 4%, saturated fat by 6%, sugar by 9%, and sodium by 4%, and dietary fiber could increase by 14%. Healthier versions of most products ranged from an average of 3 to 12 cents more per serving, but not all healthier versions were more costly. Overall, reformulation is a potential avenue for improving diet quality in households with children and adolescents, but price could be a barrier to purchasing healthier products for some households.