Template:Physician education and training in the United States Editor-In-Chief: C. Michael Gibson, M.S., M.D. 
A fellowship is the period of medical training that a physician may undertake after completing a residency. In the North American system, this refers to a period of one or more years during which the physician takes training in a sub-specialty, such as cardiology or oncology. During this time, the physician is known as a fellow. Although their training is more advanced than that of residents, fellows usually continue to treat patients under the supervision of an attending physician; their role is generally that of a consultant, advising the general medical or surgical services in the area of the fellow's sub-specialty. The attending physician supervising the fellow has already completed a fellowship in the relevant sub-specialty, and is permitted to practice without direct supervision by other physicians. Fellows are capable of acting as an attending physician in the generalist field in which they were trained, such as internal medicine or pediatrics.
Recognized Internal Medicine Fellowships
Most medical sub-specialties have formalized fellowship programs that are accredited by the Accreditation Council for Graduate Medical Education (ACGME).