Medical residency lasts three to seven years after medical school, depending on the specialty. The shortest residencies, like family medicine and internal medicine, take three years. The longest, like neurosurgery, take seven. Most doctors spend their entire residency in supervised clinical training, though some programs build in a dedicated research year.
The First Year: Internship
Every residency begins with an intern year, also called PGY-1 (postgraduate year one). Interns are licensed doctors who hold their M.D. or D.O. degrees, but they practice under direct supervision. After completing this year, a doctor can technically practice as a general practitioner, but the vast majority continue training through the remaining years of their residency to become board-eligible in a chosen specialty.
Some specialties, like neurology, require the intern year to be completed in a different field. Neurology residents, for example, spend their first year in internal medicine before starting three years of neurology-specific training, making it a four-year program total. Other fields like family medicine and surgery include the intern year as part of one continuous program.
Three-Year Residencies
The shortest residency track is three years, and it covers several of the most common medical specialties:
- Family medicine
- Internal medicine
- Pediatrics
- Emergency medicine
These are often called primary care specialties (with the exception of emergency medicine), and three years is the standard set by the Accreditation Council for Graduate Medical Education. Some family medicine programs offer a four-year option that includes extra training in areas like obstetrics, sports medicine, or rural practice. Programs that combine family medicine with another specialty, like psychiatry, can stretch to five years.
Four- to Five-Year Residencies
Specialties that involve procedural skills or a broader scope of practice generally require four or five years. Obstetrics and gynecology takes four years. Neurology takes four years total (one preliminary year plus three specialty years). Orthopedic surgery and urology each require five years of training.
General surgery is listed at five clinical years by most programs, though some institutions add a required research year, bringing the total to six. That research year is built into the residency itself, not tacked on afterward.
Six- and Seven-Year Residencies
The longest residencies belong to the most complex surgical subspecialties. Neurosurgery runs seven years at most programs, typically structured as one year of general surgery training followed by five to six years focused on the brain and spine. Plastic surgery can also reach eight or more years total if a resident completes a full five-year general surgery residency before entering an independent three-year plastic surgery program.
Cardiothoracic surgery follows a similar pattern: residents finish a full general surgery residency, then add two more years of specialized training. This brings the total to seven years minimum.
Combined Residency Programs
Some residents train in two specialties at once through combined programs. The most popular is internal medicine-pediatrics (Med-Peds), which takes four years instead of the six it would take to complete both residencies separately. The shared knowledge base between the two fields allows programs to streamline the training. Graduates are board-eligible in both internal medicine and pediatrics.
Other combined tracks pair emergency medicine with internal medicine or family medicine with psychiatry. These typically run four to five years, saving a year or two compared to completing each residency back to back.
Fellowship Adds One to Three More Years
Residency gets you board-certified in a broad specialty. If you want to subspecialize further, fellowship training follows. Fellowships typically last one to three additional years and cover areas like cardiology, gastroenterology, oncology, or sports medicine.
A cardiologist, for example, completes three years of internal medicine residency, then three more years of cardiology fellowship, for a total of six years of post-medical school training. An orthopedic surgeon who wants to specialize in hand surgery finishes five years of residency and adds a one-year fellowship. These extra years are optional but required for subspecialty board certification.
Total Training Time From Start to Finish
When you add up undergraduate education (four years), medical school (four years), and residency (three to seven years), a doctor’s training spans 11 to 15 years after high school. Subspecialists who complete fellowships can be in training for 16 to 18 years total. Physicians pursuing research-heavy tracks may add another one to two years of protected research time during residency, extending the timeline further.
The practical difference matters. A family medicine doctor can be fully trained and practicing independently by age 29 or 30. A neurosurgeon finishing fellowship might not reach that point until 36 or 37. Both paths begin with the same four years of medical school, but diverge sharply once residency begins.