A medical intern is a doctor in their first year of residency training, known formally as a Post-Graduate Year 1 (PGY-1) resident. They’ve completed four years of medical school, earned their MD or DO degree, and are now treating patients in a hospital under supervision. It’s the bridge between being a student and practicing medicine independently.
The term “intern” is actually unofficial. The Accreditation Council for Graduate Medical Education (ACGME), which oversees residency programs in the United States, stopped using it back in 1975. The official designation is PGY-1 resident. But the word stuck, and hospitals, patients, and even doctors themselves still use it daily.
What Interns Actually Do
Interns are the front line of hospital care. They’re typically the first doctor a newly admitted patient sees, and they’re responsible for evaluating that patient, taking a full medical history, performing a physical exam, and putting together an initial plan for workup and treatment. That plan then gets discussed with a more senior resident or attending physician before anything moves forward.
On a daily basis, interns round on their patients each morning, checking in on how they’re doing, reviewing overnight lab results, and proposing adjustments to the treatment plan. They write the bulk of the clinical documentation: admission notes, daily progress notes, and discharge summaries. They order tests, interpret results, coordinate with nurses and specialists, and handle the constant stream of pages and calls that come with managing a panel of sick patients. The workload is heavy and the learning curve is steep, which is why the intern year has a reputation as the most demanding year of training.
How Supervision Works
Interns don’t practice alone. ACGME rules require that PGY-1 residents start under direct supervision, meaning a more experienced physician is physically present during key parts of patient encounters. This is stricter than what’s required for senior residents, who may work under indirect supervision (a supervising doctor is immediately available but not in the room) or oversight (a supervisor reviews the case and gives feedback afterward).
As the year progresses and an intern demonstrates competence, programs can loosen the reins. The level of supervision is tailored to the individual resident’s ability and the complexity of the patient. A confident intern managing a straightforward pneumonia case might have more autonomy than one handling a complicated post-surgical patient. Senior residents, typically in their second or third year, also play a teaching and supervisory role for interns, creating a layered system where multiple levels of experience overlap.
Categorical, Preliminary, and Transitional Internships
Not all intern years are the same. A categorical position is part of a full residency program. If you match into a categorical internal medicine spot, for example, your intern year is simply year one of a three-year commitment, and you continue in the same program until you’re board-eligible in that specialty.
A preliminary position is different. It offers only one to two years of training, usually as a prerequisite for an advanced specialty that starts at PGY-2. Someone headed into dermatology or radiology, for instance, often needs to complete a preliminary year in internal medicine or surgery first, then move to their specialty program. Transitional year programs fall into this same category. They blend rotations across multiple specialties and are designed as standalone preliminary training years.
Medical students applying through the Match often apply to both a preliminary and an advanced position simultaneously, since the advanced program doesn’t begin until the preliminary year is finished.
Work Hours and Pay
ACGME caps resident duty hours at 80 per week, averaged over four weeks. That’s still roughly double a standard full-time job. Interns work long shifts that include overnight call, weekend rotations, and holiday coverage. The intensity varies by specialty and rotation, but 60 to 80 hour weeks are common, and the emotional weight of caring for seriously ill patients adds to the strain.
Compensation reflects the trainee status of the role. A PGY-1 resident at George Washington University, for instance, earns about $74,927 per year as of 2026. Salaries vary by institution and region but generally fall in the $60,000 to $80,000 range nationally. When you divide that by the hours worked, the effective hourly rate is modest. Benefits typically include health insurance, malpractice coverage, and a small stipend for educational expenses.
Licensing and the Path Forward
Even though interns have a medical degree, they don’t yet hold a full, unrestricted medical license. That requires passing all three parts of the United States Medical Licensing Examination (USMLE for MD graduates) or the equivalent for DO graduates. Most residency programs require interns to pass the final licensing exam, Step 3, during their first year in order to advance to PGY-2. Passing is necessary for full licensure, the ability to prescribe controlled substances, and the option to moonlight (pick up extra clinical shifts for additional pay).
After completing the intern year, residents continue training for a total that depends on their specialty. Primary care fields like family medicine and internal medicine require three years total. Surgical specialties can require five to seven. Once residency is complete, physicians can pursue additional fellowship training in a subspecialty or begin independent practice. The intern year, grueling as it is, is the foundation everything else is built on.