The highest-earning occupation in the United States appears to be doctors. According to data from the U.S. Bureau of Labor Statistics (BLS), 19 of the top 20 highest-paying occupations were doctors or dentists, and the only non-medical occupation included airline pilots, which ranked 20th. According to USA Today on the 5th (local time), 19 of the top 20 highest paying jobs in the United States were doctors or dentists. Pediatric surgeons earned an average annual salary of $450,810 (approximately 689.88 million won), cardiologists earned $432,490, and orthopedic surgeons earned $365,060. Occupations with higher incomes than this were limited to a few high-income professionals, such as CEOs of large corporations or partner lawyers at large law firms. So why do American doctors earn such high income? The first factor is the long education and training period and high work intensity. According to a joint study by Harvard University and the University of Minnesota, U.S. doctors earn higher income than doctors in other Organization for Economic Co-operation and Development (OECD) countries.