Where the money goes: The evolving expenses of the US health care system

National health care expenditures constitute revenue to the health care system. However, little is known about how this revenue is distributed across sectors. This article calculates revenues and detailed expenditures for physicians' offices, hospitals, and outpatient care centers in 1997, 2002, 2007, and 2012, using a range of Census Bureau and Bureau of Labor Statistics sources. Between 1997 and 2012, spending on these three sectors rose by $580 billion, and employment rose by 1.7 million people. Just under half of all 2012 revenues were spent on labor compensation. The labor compensation share of spending declined slightly; within these sectors, the share of compensation paid to physicians and nurses increased. Although employment of nonprofessional labor grew during the study period, this group did not account for much of the sector's increased spending. The plurality of the 1997-2012 spending increase went to producers of purchased materials and services, which now account for more than one-third of payments.