Medical schools fall into two categories, research and primary care. "U.S. News and World Report" ranked the best colleges for the medical field. The rankings are based on a variety of data, including faculty to student ratio, admission statistics and research activity.

Harvard Medical School

As of 2010, Harvard ranks first among research focused institutions. Located in Boston, Harvard's medical school is affiliated with several hospitals, including Beth Israel Deaconese Medical Center, Cambridge Health Alliance, Children's Hospital Boston, Forsyth Institute, Massachusetts General Hospital and Spaulding Rehabilitation Hospital. Harvard offers programs leading to doctor of medicine degrees, doctorates, dental medicine degrees and postdoctoral fellowships. Its research facilities are housed in the 1906 quadrangle and include basic and science departments.

University of Washington Medicine

Founded in 1946, UW is No. 1 in primary care and No. 6 for research, giving students the option to pursue either track at a high-quality institution. Academic courses cover cardiology, gastroenterology, internal medicine, oncology and rheumatology in addition to various medical programs in neurology, microbiology, family medicine, radiology and pediatrics. The medical school is in Seattle but operates programs nationally and internationally, researching all aspects of health and disease. UW medical school had 901 graduates in 2010.

University of California at San Francisco

UCSF School of Medicine ranks fourth for research and fifth in primary care in the nation. The school offers graduate degrees in biological, biomedical, pharmaceutical, nursing, social and behavioral sciences. There are 19 degree programs, all ranked in the top 10 in the United States. In 2003, the school boasted $420.7 million in research grants. Multiple researchers have won a Nobel Prize while working with UCSF as well as MacArthur Foundation Genius awards, Gairdner International Prize for outstanding contributions to medical science and the Lemelson-MIT Prize for invention and innovation.

University of Pennsylvania

Located in Philadelphia, UPenn's School of Medicine has 1,700 full-time faculty members and 725 medical students with 1,000 residents and fellows. Ranked second in research and seventh in primary care, UPenn is one of the oldest medical schools in North America having been founded in 1765. In research, UPenn's School of Medicine operates 28 basic and clinical departments and received $556 million in support for research in 2007. It also is affiliated with major hospitals in the area, including Hospital of the University of Pennsylvania, Penn Presbyterian Medical Center and Pennsylvania Hospital. It has multiple centers and institutes, including Abramson Cancer Center, Center for Bioethics, Center for Research on Reproduction in Women's Health, Institute for Environmental Medicine, The Mahoney Institute of Neurological Sciences and nearly 40 department centers.