STATISTICAL BRIEF #421:  Differentials in the Concentration in the Level of Health Expenditures across Population Subgroups in the U.S., 2010. Steven B. Cohen PhD and Namrata Uberoi, MPH- Agency for Healthcare Research and Quality. August 2013

• ‘In 2010, the top 1 percent ranked by their health care expenses accounted for 21.4 percent of total health care expenditures with an annual mean expenditure of $87,570. Overall, the top 50 percent of the population ranked by their expenditures accounted for 97.2 percent of overall health care expenditures while the lower 50 percent accounted for only 2.8 percent of the total.
• Children under the age of 18 were characterized by substantially greater concentrated levels of health care spending relative to their older counterparts. Alternatively, the elderly had the highest mean levels of health care expenditures relative to younger population subgroups at the top quantiles of the expenditure distribution.
• The top 5 percent of the uninsured population under age 65 ranked by their health care expenses accounted for 67.3 percent of the health care expenditures incurred by this subpopulation with an annual mean of $17,453. Conditioned on insurance coverage status, the uninsured had the most concentrated levels of health care expenditures and the lowest annual mean expenses.
• The top 5 percent of individuals with four or more chronic conditions accounted for 29.7 percent of health care expenditures for this subpopulation with an annual mean of $81,790. Based on chronic condition status, persons with four or more chronic conditions had the lowest concentrated levels of health care expenditures and the highest annual mean expenses at the top quantiles of the expenditure distribution.”