It is a first professional degree (qualifying degree) in some countries, including the United States and Canada, although training is entered after obtaining at least 90 hours of university level work (see second entry degree). In other countries, such as United Kingdom and Australia, the MD is a higher doctoral academic research degree resembling a PhD. In Britain and many Commonwealth nations, the qualifying medical degree is instead the Bachelor of Medicine, Bachelor of Surgery (MBBS or MBChB).
According to Sir John Bagot Glubb, Syed Farid Alatas, and S. M. Imamuddin, the first medical schools to issue academic degrees and diplomas were the teaching Bimaristan (Hospitals)of the medieval Islamic world. The first of these institutions was opened in Baghdad during the time of Harun al-Rashid. They then appeared in Egypt from 872 and then in Islamic Spain, Persia and the Maghreb thereafter. Physicians and surgeons at these hospital-universities gave lectures on Islamic medicine to medical students and then a medical diploma or degree was issued to students who were qualified to be practicing physicians.
According to Douglas Guthrie, who bases his account on L Thorndike, medical men were first called "Doctor" at the Medical School of Salerno. He states that the Emperor Frederick II decreed in 1221 that no one should practice medicine until he had been publicly examined and approved by the masters of Salerno. The course lasted 5 years, and to start one had to be 21 years old and show proof of legitimacy and of three years study of logic. The course was followed by a year of supervised practice. After the laureation ceremony the practitioners could call themselves "magister" or "doctor."
The MB or Bachelor of Medicine was also the first type of medical degree to be granted in the United States and Canada. The first medical schools that granted the MB degree were Penn, Harvard, Toronto, Maryland, and Columbia. These first few North American medical schools that were established were (for the most part) founded by physicians and surgeons who had been trained in England and Scotland. University medical education in England culminated with the MB qualification, and in Scotland the MD, until from the mid-19th century the public bodies who regulated medical practice at the time required practitioners in Scotland as well as England to hold the two the dual Bachelor of Medicine and Bachelor of Surgery degrees (MB BS/MBChB/MB BChir/BM BCh etc). North American Medical schools switched to the tradition of the Ancient universities of Scotland and began granting the MD title rather than the MB mostly throughout the 1800s. The Columbia University College of Physicians and Surgeons in New York (which at the time was referred to as King's College of Medicine) was the first American University to grant the MD degree instead of the MB.
Within the United States, MDs are awarded by LCME-accredited medical schools.   . The Liaison Committee on Medical Education is an independent body sponsored by the Association of American Medical Colleges and the American Medical Association, the AMA.
Admissions to medical schools in the United States is highly competitive, with 17,800 of the approximately 47,000 applicants matriculating to any medical school. Before entering medical school students must complete a four year undergraduate degree (usually in science) and take the Medical College Admissions Test (MCAT). Before graduating from a medical school and achieving the degree of Medical Doctor, students have to pass the United States Medical Licensing Examination (USMLE) Step 1 and to take (but not necessarily pass) both the Clinical Knowledge and Clinical Skills parts of Step 2. The MD degree is typically earned in four years. Following the awarding of the MD, physicians who wish to practice in the United States are required to complete at least one internship year (PGY-1) and pass the USMLE Step 3. In order to receive Board Eligible or Board Accredited status in a specialty of medicine such as general surgery or internal medicine, then undergo additional specialized training in the form of a residency. Those who wish to further specialize in areas such as cardiology or interventional radiology then complete a fellowship. Depending upon the physician's chosen field, residencies and fellowships involve an additional three to eight years of training after obtaining the MD. This can be lengthened with additional research years, which can last one, two, or more years.
In Canada, the MD is the basic medical degree required to practice medicine. At McGill University in Montreal, M.D., C.M. (Medicinae Doctor et Chirurgiae Magister or a Doctor of Medicine and Master of Surgery sometimes also written MDCM) degrees are awarded.
Even though the MD is a first professional degree and not a doctorate of research (ie. PhD), many holders of the MD degree conduct clinical and basic scientific research and publish in peer-reviewed journals during training and after graduation. Medical Scientist Training Programs (MSTPs) are offered at many universities which are a combined medical degree and PhD. Some MDs choose a research career and receive funding from the NIH as well as other sources such as the Howard Hughes Medical Institute. A few even go on to become Nobel Laureates.
In the United Kingdom and Ireland (and many Commonwealth countries) the MD is a postgraduate research degree in medicine. At some universities, this takes the form of a first doctorate, analogous to the PhD, awarded upon submission of a thesis and a successful viva. The thesis may consist of new research undertaken on a full- or part-time basis, with much less supervision (in the UK) than for a PhD, or a portfolio of previously-published work.
At some other universities (especially older institutions such as Oxford and Cambridge) the MD is a higher doctorate (similar to a DSc) awarded upon submission of a portfolio of published work representing a substantial contribution to medical research. .
In the case where the MD is awarded (either as a first or higher doctorate) for previously-published research, the candidate is usually required to be either a graduate or a full-time member of staff, of several years' standing of the university in question.
The University of Buckingham, the only private university in Great Britain, has announced an Indian-style two year full-time taught course for a "Clinical MD" in internal medicine. This is designed for non-European Union graduates, who are no longer to be allowed to take accredited training posts in UK hospitals. This degree will be awarded first in 2010.
The entry-level first professional degree in these countries for the practice of medicine is that of Bachelor of Medicine and Bachelor of Surgery (MBBS, MB, MB BCh BAO, BMBS, MBBChir, or MBChB). This degree typically requires between four and six years of study and clinical training, and is equivalent to the North American MD degree.
The University of Melbourne in Australia has announced plans to introduce the Doctor of Medicine (MD) in 2011 as their first professional degree in medicine for graduates of the Bachelor of Biomedicine or a Bachelor of Science degree. The university will become the first in Australia to leave the Bachelor of Medicine and Bachelor of Surgery (MBBS) and offer the MD as a first professional degree in medicine rather than as a research degree.
In India, an MD is a higher postgraduate degree awarded by many medical colleges to medical graduates holding the MBBS degree