In the wake of national health reform, health systems, health plans, providers, and policy makers will be discussing what can be done to contain health care costs—within the provisions of reform or beyond them. For that discussion, it will be important to understand that health care spending is not distributed evenly across the population—or by condition. In fact, just five percent of the U.S. population—those with the most complex and extensive medical conditions—accounts for almost half (49 percent) of total U.S. health care spending, and 20 percent of the population accounts for 80 percent of total spending.

Chronic conditions are the leading cause of death and disability in the U.S.1, and treating patients with comorbid chronic conditions costs up to seven times as much as treating patients who have only one chronic condition.2 Modifiable health risk factors, such as cigarette smoking and overweight/obesity, are responsible for much of the illness, healthcare utilization, and subsequent costs related to chronic disease.