The researchers studied the sources of cost growth among the privately insured by analyzing the contributions to higher spending of changes in prices and changes in the number and types of services performed. They also examined how changes in prices and changes in the number and types of services have differentially affected different categories of spending and different demographic groups. These findings for the privately insured were also compared to trends in cost growth in public programs. The researchers explored which policies or benefit designs will be more effective in reducing spending, as well as whether costs are driven more by increased utilization of certain types of services or by increases in the prices of particular services. In addition, the researchers suggested that the findings would be useful in developing policies to expand coverage by identifying the sources of cost increases that may affect coverage rates. The objective of this study was to provide information for policymakers to design interventions to reduce health spending in ways that benefit consumers.