The Milliman Medical Index 2007 (MMI), which marks the third annual release of this report, measures average medical spending for a typical American family of four covered by an employer-sponsored Preferred Provider Organization (PPO) program. It provides a consistent healthcare benefit cost benchmark by annually assessing the changes in those costs over a five year period. Unlike medical cost surveys that focus exclusively on employer cost increases, the MMI examines the total cost to deliver healthcare and how this cost is allocated between the employer and the employee. The MMI also looks at key components of actual medical spending and charts the changes in these components over time. In addition to national trends, the MMI includes results for seven major American metropolitan areas to illustrate how widely medical costs can vary by region.