6. Massachusetts General Hospital
Located in Boston, MGH, which is the third-oldest hospital in the United States, is also the teaching hospital of Harvard Medical School, the pre-eminent medical school in the country, with virtually all of its physicians serving as Harvard Med faculty.
With an annual research budget of more than $912 million, it also has the largest hospital-based research program; over 1,200 clinical trials are conducted at Mass General at any given time, and in 2016–17 MGH topped the Nature Index list, publishing more articles in “high-impact” journals than any other hospital in America. Current projects include combating the opioid epidemic and studying the impact of social and economic status on health.