Health care in the United States is provided by many separate legal entities. 
The U.S. spends more on health care per capita than any other nation in the world.[1] Current estimates put U.S. health care spending at approximately 15.2% of 
GDP, second only to the tiny Marshall Islands among all 
United Nations member nations.
[1] The health share of GDP is expected to continue its historical upward trend, reaching 19.5 percent of GDP by 2017.
[2] In 2007, the U.S. spent a projected $2.26 trillion on health care, or $7,439 per person.[3] According to the Institute of Medicine of the National Academy of Sciences, the U.S. is the only wealthy, industrialized nation that does not have a universal health care system.[4] In the 
United States, around 84.7% of citizens have some form of 
health insurance; either through their employer (59.3%), purchased individually (8.9%), or provided by government programs (27.8%; there is some overlap in these figures).
[5] Certain 
publicly-funded health care programs help to provide for the elderly, disabled, children, veterans, and the poor, and federal law mandates public access to emergency services regardless of ability to pay. 
U.S. government programs accounted for over 45% of health care expenditures, making the U.S. government the largest insurer in the nation. Per capita spending on health care by the U.S. government placed it among the top ten highest spenders among United Nations member countries in 2004.[6]
 Americans without health insurance coverage at some time during 2007 totaled about 15.3% of the population, or 45.7 million people.
[5] Health insurance costs are rising faster than wages or inflation, and "medical causes" were cited by about half of bankruptcy filers in the United States in 2001.[7]
 The debate about U.S. health care concerns questions of access, efficiency, and quality purchased by the high sums spent. 
The World Health Organization (WHO) in 2000 ranked the U.S. health care system first in both responsiveness and expenditure, but 37th in overall performance and 72nd by overall level of health (among 191 member nations included in the study).[8][9] The WHO study has been criticized both for its methodology and for a lack of correlation with user satisfaction ratings.
[10][11]