A medical intern and a resident are nearly the same thing. An intern is simply a first-year resident, someone in their initial year of hands-on training after graduating medical school. The term “internship” was officially retired by the organization that oversees residency programs back in 1975, but it stuck in everyday language. Today, the formal label is PGY-1, short for “postgraduate year one.”
Why the Terms Still Cause Confusion
The Accreditation Council for Graduate Medical Education (ACGME) stopped using the word “intern” nearly five decades ago, replacing it with the PGY numbering system. PGY-1 is your first year, PGY-2 your second, and so on through the end of training. Despite this, hospitals, patients, and even doctors themselves still casually refer to first-year residents as interns. So if you hear someone called an intern, they’re a fully licensed physician in training, not a college student shadowing for credit.
Every resident, regardless of year, holds a medical degree. They’ve completed four years of medical school, passed their licensing exams, and matched into a training program. The difference between a PGY-1 and a PGY-4 is experience and autonomy, not education level.
How Interns Spend Their Days
First-year residents handle the frontline work of patient care. They consult with patients and families, write medical orders, update electronic health records, and coordinate with nurses, technicians, and consulting physicians. It’s a steep learning curve. Much of the year is spent getting comfortable with the rhythm of hospital work: knowing when to act independently and when to ask for help.
The key feature of intern year is close supervision. Senior residents and attending physicians (fully trained doctors who oversee the team) are available to step in when things don’t go as planned. Interns are expected to manage patients directly, but they aren’t making high-stakes decisions alone. Think of it as the training-wheels phase of being a doctor, where real responsibility comes with a safety net.
How Senior Residents Differ
As residents advance through their PGY years, their role shifts from doing the groundwork to leading the team. A third- or fourth-year resident might supervise a group of interns, make more complex clinical decisions, and take on teaching responsibilities. They also gain more independence. The ACGME defines different levels of supervision, ranging from a senior physician physically present during a procedure to simply being available by phone. Interns typically operate under tighter oversight, while senior residents earn progressively looser reins.
By the final year of residency, a trainee is functioning close to the level of an independent physician. They’re still technically supervised, but their attending may only review decisions after the fact rather than in real time.
How Long Residency Lasts
The total length of residency depends entirely on the specialty. Some of the most common timelines:
- Internal medicine: 3 years
- Pediatrics: 3 years
- Emergency medicine: 3 to 4 years
- General surgery: 5 years
- Plastic surgery: 6 years
- Neurosurgery: 7 years
These are the minimum years of postgraduate training required before a physician can sit for board certification in that specialty. Some doctors then add fellowship training on top, which can tack on one to three more years for a subspecialty like cardiology or surgical oncology.
Categorical vs. Preliminary Positions
Not all residency spots work the same way. A categorical position is the standard track: you match into a program and train there from PGY-1 through completion, earning full board eligibility in that specialty. A preliminary position, by contrast, offers only one to two years of training. It’s designed as a stepping stone for doctors who will move into a different advanced specialty program afterward.
For example, someone heading into a field like radiology or dermatology might need a preliminary year of internal medicine or surgery before starting their specialty training elsewhere. Transitional year programs, which rotate trainees through several departments, also fall into this preliminary category. These distinctions matter because they determine whether a doctor’s first year is part of a continuous track or a standalone bridge year.
Work Hours and Pay
Residency is notoriously demanding. ACGME rules cap clinical and educational work at 80 hours per week, averaged over a four-week period. That includes everything: shifts, teaching sessions, clinical work done from home, and any moonlighting. Residents must also get at least one day off per week (averaged over four weeks) and at least 14 hours free after a 24-hour in-house shift. Programs that regularly schedule residents right up to the 80-hour limit are expected to build in buffer time so that staying late for a patient doesn’t push trainees over the cap.
Pay is modest relative to the hours. At one major academic medical center, PGY-1 residents earn about $72,700 per year, rising to roughly $79,100 by PGY-3. That works out to well under $20 per hour when you factor in the actual time worked. Salaries vary somewhat by institution and region, but the general range is similar across the country. The significant pay jump comes after residency, when physicians enter practice or join a group.
How Doctors Get Placed
Medical students don’t simply apply and accept a residency offer the way you might with a regular job. Instead, they go through the National Resident Matching Program, commonly called “the Match.” Students apply to programs during their final year of medical school, interview over several months, and then submit a ranked list of their preferred programs. Programs do the same with applicants. A computer algorithm pairs them up, and on Match Day (March 20 in 2026), students find out where they’ll train.
The algorithm is designed to favor applicants, so students are encouraged to rank their top-choice program first even if it feels like a long shot. About 93 to 95% of applicants from U.S. medical schools match successfully. Those who don’t can seek unfilled positions through a supplemental process that runs during Match Week.
The Licensing Timeline
Graduating medical school alone doesn’t grant a full, unrestricted medical license. Residents practice under a training permit while completing their postgraduate years. In most states, a physician needs at least two to three years of postgraduate training before qualifying for a full license. This means an intern, despite being a doctor with a medical degree, is still years away from being able to practice completely independently. The residency structure exists precisely to bridge that gap between classroom knowledge and the judgment that comes from treating thousands of patients under supervision.