MD stands for Doctor of Medicine, from the Latin “Medicinae Doctor.” It is the standard medical degree awarded in the United States and Canada, qualifying graduates to diagnose and treat illness, prescribe medications, perform surgery, and practice in any medical specialty. Earning an MD requires a minimum of eight years of education after high school, followed by several more years of hands-on residency training.
What an MD Can Do
An MD is a fully licensed physician with a broad scope of practice. That includes prescribing medications (including controlled substances), ordering and interpreting diagnostic tests like MRIs, CT scans, and bloodwork, diagnosing conditions, performing procedures within their specialty, admitting patients to hospitals, and overseeing inpatient care. There is no medical specialty off-limits to an MD. They work in primary care, surgery, cardiology, emergency medicine, neurology, psychiatry, and every other branch of medicine.
How Long It Takes to Become an MD
The path starts with a four-year undergraduate degree, typically with coursework in biology, chemistry, physics, and organic chemistry. During college, aspiring physicians also build clinical experience through volunteering, shadowing doctors, and research. Before applying to medical school, they take the MCAT, a standardized exam that tests scientific reasoning and critical thinking.
Medical school itself is another four years. The first one to two years focus on classroom learning in the foundational sciences: anatomy, pharmacology, pathology, and similar subjects. The remaining years shift to clinical rotations, where students work directly with patients in hospitals and clinics across different specialties.
After earning the MD degree, new doctors enter a residency, a period of supervised training in their chosen specialty. Residency length varies significantly. Internal medicine and pediatrics require three years. General surgery takes five. Neurological surgery is seven years. Physicians who want to specialize further, such as a cardiologist training within internal medicine, complete an additional fellowship of one to three years after residency. All told, the journey from college freshman to independently practicing specialist can take 11 to 16 years.
Licensing Exams
Graduating from medical school alone doesn’t grant a license to practice. MD students must pass a three-part national licensing exam taken at different stages of their training. The first part tests foundational science knowledge and is typically taken during medical school. The second assesses clinical knowledge and the ability to apply it to patient care. The third, usually taken during residency, evaluates readiness for unsupervised practice. Passing all three parts is required to obtain a state medical license.
Board Certification
Once licensed, many physicians pursue board certification in their specialty. This is a voluntary credential, but most hospitals and insurance networks expect it. To become board certified, a physician must complete an accredited residency (three to seven years depending on the specialty), obtain an unrestricted medical license, secure letters of attestation from their training program, and pass a specialty-specific exam. Subspecialists go through a similar process again after completing additional fellowship training.
MD vs. DO
The other medical degree granted in the United States is the DO, or Doctor of Osteopathic Medicine. In practice, MDs and DOs have the same scope of practice and the same career options. Both complete four years of medical school, train in residency programs, and can prescribe medications, perform surgery, and specialize in any field.
The differences are mostly philosophical and curricular. DO programs have historically emphasized a holistic, whole-body approach and include training in osteopathic manipulative treatment, a set of hands-on techniques involving stretching, gentle pressure, and resistance applied to muscles and joints. This adds extra focus on the musculoskeletal system during DO training. Beyond that added coursework, the day-to-day education follows the same structure, and patients receiving care from an MD or a DO can expect the same standard of evidence-based medicine.
MD vs. MBBS Outside the U.S.
In countries that follow the British medical education system, including India, the UK, Australia, and much of Africa, the equivalent degree is the MBBS (Bachelor of Medicine and Bachelor of Surgery). The MBBS is an undergraduate degree, meaning students enter medical training directly after secondary school rather than completing a separate bachelor’s degree first. In a global context, the MBBS is considered equivalent to the North American MD for purposes of medical licensure.
An MBBS graduate who wants to practice in the United States must pass the same three-step licensing exam that American MD graduates take, obtain certification from a credentialing body, and complete a U.S.-accredited residency program. Residency programs sometimes give preference to MD holders over international MBBS graduates, and many MBBS-trained physicians pursuing American careers choose to earn an MD as well.
Salary and Job Outlook
Physicians and surgeons in the United States earned a median annual wage equal to or greater than $239,200 as of May 2024, according to the Bureau of Labor Statistics. Compensation varies widely by specialty, with primary care physicians on the lower end and surgical subspecialists and certain procedural specialists earning significantly more. Employment of physicians is projected to grow about 3 percent from 2024 to 2034, roughly matching the average growth rate across all occupations. An aging population and expanding access to healthcare continue to sustain demand.