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PhD vs MD – Differences explained


A MD is a Doctor of Medicine, whilst a PhD is a Doctor of Philosophy. A MD program focuses on the application of medicine to diagnose and treat patients. A PhD program research focuses on research (in any field) to expand knowledge.


This article will outline the key differences between a MD and a PhD. If you are unsure of which degree is suitable for you, then read on to find out the focuses and typical career paths of both. Please note this article has been written for the perspective of a US audience.

What is a MD?

MD (also seen stylized as M.D and M.D.) comes from the Latin term Medicīnae Doctor and denotes a Doctor of Medicine.

Definition of a MD (Cambridge Dictionary)
“Doctor of Medicine: a degree that someone must have to work as a doctor, or a person who has this degree”.

MDs practice allopathic medicine (they use modern medicine to treat symptoms and diseases). A common example would be your physician, though there are numerous types of medical doctors, with different areas of speciality and as such may be referred to differently.

What is a PhD?

A PhD (sometimes seen stylized as Ph.D.) comes from the Latin term Philosophiae Doctor and denotes a Doctor of Philosophy.

Definition of a PhD (Cambridge Dictionary)
“Doctor of philosophy: the highest college or university degree, or someone who has this”.

A PhD can be awarded for carrying out original research in any field, not just medicine. In comparison to an MD, a PhD in a Medicinal field is focused on finding out new knowledge, as opposed to applying current knowledge.

A PhD in Medicine therefore does not require you to attend medical school or complete a residency program. Instead, you are required to produce a thesis (which summarizes your research findings) and defend your work in an oral examination.

What is the difference between a MD and a PhD?

Both are Doctoral Degrees, and someone with either degree can be referred to as a doctor. But for clarity, MDs are awarded to those with expertise in practicing medicine and are therefore more likely to be found in clinical environments. PhDs are awarded to researchers, and are therefore more likely to be found in academic environments.

This does not mean that MDs cannot pursue a research career, nor does it mean that a PhD cannot pursue clinical practice. It does mean, however, that PhDs are more suited to those who would wish to pursue a career in research, and that MDs are more suited to those who prefer the clinical aspects of medicine or aspire to become a practicing physician.

It should also be noted that a medical PhD doctorates possess transferable skills which make them desirable to various employers. Their familiarity with the scientific method and research experience makes them well suited to industry work beyond medical research.

Program structure and time:

The standard MD program structure sees students undertake 2 years of coursework and classroom-based learning, before undertaking 2 years of rotational work in a clinical environment (such as a hospital). Getting an MD requires attending a medical school (accredited by the Liaison Committee on Medical Education) and completing a residency program. Both of which prepare students to diagnose patients and practice clinical medicine.

The standard PhD program lasts 5 to 7 years and sees students undertake original research (monitored by a supervisor). Getting a PhD requires the contribution of novel findings, which leads to the advancement of knowledge within your field of research. With the exception of some clinical PhDs, a PhD alone is not enough to be able to prescribe medicine.

PhD doctorates are required to summarize the purpose, methodology, findings and significance of their research in a thesis. The final step is the ‘Viva Voce’ where the student must defend their thesis to a panel of examiners.

To summarize, a MD program usually lasts 4 years, whilst a PhD program lasts 5 to 7 years. Before being licensed to practice medicine, however, you must first complete a residency program which can last between 3 to 7 years.

What is a MD/PhD?

A MD/PhD is a dual doctoral degree. The program alternates between clinical focused learning and research focused work. This is ideal for those who are interested in both aspects of medicine. According to the Association of American Medical Colleges, an estimated 600 students matriculate into MD-PhD programs each year.

The typical length of a MD/PhD program is 7 to 8 years, almost twice the length of a MD alone. As with a MD, MD/PhDs are still required to attend medical school and must complete a residency program before being able to practice medicine.

In comparison to PhD and MD programs, MD/PhD positions in the United States are scarce and consequently more competitive. The tuition fees for MD/PhD positions are typically much lower than MD and PhD positions are sometimes waived completely.

Those who possess a MD/PhD are commonly referred to as medical scientists. The ability to combine their medical knowledge with research skills enables MD/PhDs to work in a wide range of positions from academia to industrial research.

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