In the medical residency vs internship comparison, the internship is not a separate stage. It is the first year of residency. An intern is a first-year resident, called a PGY-1 (postgraduate year 1), and residency is the full accredited training program of three to seven years that leads to board eligibility and independent practice.
So when a doctor says “I’m an intern,” they hold an MD or DO, they have matched into a residency position, and they are in month one through twelve of graduate medical education. For the bigger picture of the training ladder, IMA’s guide to how residency and fellowship work covers what comes after medical school.
Medical Residency vs Internship at a Glance
| Feature | Internship (intern year) | Residency (full program) |
|---|---|---|
| What it is | The first year of graduate medical education | The whole accredited training program in one specialty |
| Training level | PGY-1 only | PGY-1 through the final year (PGY-3 to PGY-7 for most core specialties) |
| Length | 12 months | 36 months (internal medicine, family medicine) to 84 months (neurological surgery) |
| Who you are | Intern, or first-year resident | Resident; senior residents and chief residents in later years |
| Program types | Categorical first year, preliminary year, or transitional year | Categorical program, or an advanced program that starts at PGY-2 |
| Supervision | Must start under direct supervision | Moves to indirect supervision and oversight as skills are shown |
| Licensing step | USMLE recommends at least one postgraduate year, or near completion of one, before Step 3 | A full license once the state’s training rule is met (one year in New York for U.S. graduates) |
| Pay (AAMC, July 1, 2025) | $68,166 mean pay for program year 1 | $70,499 mean pay in year 2, $73,301 in year 3, rising each year |
| What it leads to | PGY-2 in the same program or an advanced program | Board eligibility, then attending practice or a fellowship |
The table answers the core question: every intern is a resident, but not every resident is an intern. The rest of this guide explains each row with the official rules behind it.
The Medical Internship Is the PGY-1 Year
A medical internship is the PGY-1 year, the first 12 months of training after medical school graduation. The National Resident Matching Program (NRMP) fills these positions through the Main Residency Match. In the 2026 Main Residency Match, programs offered 41,126 PGY-1 positions, an increase of 1,085 over 2025, and 48,050 active applicants submitted certified rank order lists.
Interns write orders, admit patients, present on rounds, take call, and follow their own patient list, all under supervision. It is the first year a graduate carries responsibility for patients as a physician.
The word “internship” also has a second meaning that confuses many students. Pre-med and high school students take part in clinical internships before medical school. Those programs are clinical experience for applicants, not graduate medical education. They are covered at the end of this guide.
What Are Categorical, Preliminary and Transitional Years?
The NRMP sorts residency positions into five program types, and three of them involve the intern year:
- Categorical (C): PGY-1 programs that provide the full training required for board certification in a specialty. A categorical intern in internal medicine stays in the same program for all 36 months.
- Preliminary (P): one-year transitional or specialty programs, such as a preliminary year in medicine or surgery. The intern then moves to a different program for PGY-2.
- Advanced (A): specialty programs that begin the year after the Match, after one or more years of required preliminary training.
- Categorical Primary Care (M): PGY-1 programs in medicine and pediatrics with a primary care emphasis.
- Physician (R): programs that begin in the year of the Match and are reserved for physicians with prior graduate medical education.
The transitional year is its own accredited program. ACGME program requirements state that the transitional year must be 12 months long. It must include at least 24 weeks of fundamental clinical skills rotations in emergency medicine, family medicine, general surgery, internal medicine, obstetrics and gynecology, pediatrics or critical care, at least four weeks (140 hours) of emergency medicine, and at least 140 hours of ambulatory care. ACGME describes it as preparation for specialties that require a year of fundamental clinical education, and as a year of clinical education for graduates heading into public health, military service as general medical officers, administrative medicine or research.
Which Specialties Require a Separate Intern Year?
Some specialties start at PGY-2, so the applicant needs a preliminary or transitional year first. ACGME requirements for 2026 show the pattern:
| Specialty | ACGME program formats | How the intern year works |
|---|---|---|
| Diagnostic radiology | 48 months of radiology, or a 60-month format | The 60-month format includes 12 months of fundamental clinical skills; otherwise the intern year is done separately |
| Anesthesiology | 36-month or 48-month format | The 48-month format includes 12 months of fundamental clinical skills; both include 36 months of clinical anesthesia |
| Internal medicine | 36 months | The intern year is built into the categorical program |
| Family medicine | 36 months | The intern year is built into the program |
| General surgery | 60 months | The intern year is built into the categorical program |
| Neurological surgery | 84 months | The intern year is built into the program |
In the 2026 NRMP tables, PGY-2 positions were listed for specialties including anesthesiology, dermatology, neurology, physical medicine and rehabilitation, radiation oncology and diagnostic radiology. Applicants to those programs often build a two-part rank list: the advanced program for PGY-2 onward and a preliminary or transitional program for PGY-1. IMA’s walkthrough of Match Day and how the Match works explains how rank lists turn into placements.
The Medical Residency Is the Full Training Program
Residency is the complete period of graduate medical education in one specialty, accredited in the United States by the Accreditation Council for Graduate Medical Education (ACGME). It starts with the intern year and ends when the resident completes the final program year and becomes eligible for specialty board certification. Program length is set by each specialty’s requirements. Internal medicine, for example, must provide 36 months of supervised graduate medical education.
As residents advance, they run teams, teach interns and medical students, and make more decisions on their own. The difference between a senior resident and the attending who supervises them is covered in IMA’s guide to attending physicians vs resident doctors. Residents who want more training after residency go on to a medical fellowship in a subspecialty such as cardiology or gastroenterology.
How Does Supervision Change From Intern to Senior Resident?
ACGME uses three levels of supervision, and the intern year is where the strictest one applies:
- Direct supervision: the supervising physician is physically present with the resident during the key portions of the patient interaction. ACGME requires that PGY-1 residents must initially be supervised directly.
- Indirect supervision: the supervising physician is not physically present but is immediately available for guidance and to provide direct supervision. In internal medicine, a supervising physician must be immediately available to be physically present for PGY-1 residents on inpatient rotations who have progressed to this level.
- Oversight: the supervising physician is available to review procedures and encounters and give feedback after care is delivered.
ACGME also states that PGY-1 residents are not initially allowed to take at-home call, because direct supervision, or indirect supervision with direct supervision immediately available, is not possible from home. Senior residents earn more independence as they demonstrate competence.
What Are the Work Hour Limits for Interns and Residents?
The same ACGME work hour rules apply to interns and senior residents:
- No more than 80 hours of clinical and educational work per week, averaged over four weeks, including clinical work done from home and all moonlighting.
- Work periods must not exceed 24 hours of continuous scheduled clinical assignments, plus up to four hours for transitions of care and education.
- At least 14 hours free after 24 hours of in-house call.
- At least one day in seven free of clinical work and required education, averaged over four weeks.
- In-house call no more often than every third night, averaged over four weeks.
Licensing: Where the Intern Year Fits
The intern year matters for the medical license. Medical school graduates usually hold a training license or permit during residency, and the full license depends on exams and postgraduate training.
When Do Residents Take USMLE Step 3 or COMLEX Level 3?
USMLE Step 3 is the final exam in the USMLE sequence leading to a license to practice medicine without supervision. To be eligible for Step 3, applicants need passing scores on Step 1 and Step 2 CK and an MD or DO degree, and the USMLE program recommends that applicants have completed, or be near completion of, at least one postgraduate training year. That is why many residents sit for Step 3 during or just after the intern year. Step 3 is a two-day exam; the first day alone has 232 multiple-choice items in about 7 hours.
Osteopathic residents can take COMLEX-USA Level 3, a two-day, computer-based exam the NBOME describes as assessing an osteopathic resident’s readiness for unsupervised practice.
IMA’s comparison of COMLEX and USMLE covers the full series, and the Step 2 CK guide covers the exam taken before the Match.
How Much Postgraduate Training Does a License Require?
Each state board sets its own rule, and graduates of international schools often need more years. New York is a clear example. Its physician license requirements call for at least one year of postgraduate hospital training in an accredited residency for graduates of LCME- or AOA-accredited programs, and at least three years for graduates of non-accredited programs. Because of rules like these, finishing the intern year is often the first point at which a U.S. graduate can qualify for a full license, even though they continue in residency.
International medical graduates face extra steps before and during residency. IMA’s guide for IMGs on ECFMG and the Match covers certification and visa planning.
Intern and Resident Pay by Program Year
Interns and residents are paid a salary, called a stipend, by the sponsoring institution. The AAMC Survey of Resident/Fellow Stipends and Benefits reports pay as of July 1, 2025, from 350 non-profit sponsoring institutions:
| Program year | Mean pay (unweighted) | Median pay | 25th to 75th percentile pay |
|---|---|---|---|
| Year 1 (intern) | $68,166 mean pay | $66,986 median pay | $62,830 to $71,657 pay range |
| Year 2 | $70,499 mean pay | $69,430 median pay | $65,054 to $74,258 pay range |
| Year 3 | $73,301 mean pay | $72,000 median pay | $67,055 to $77,686 pay range |
| Year 4 | $77,593 mean pay | $76,000 median pay | $71,103 to $82,225 pay range |
| Year 5 | $81,807 mean pay | $79,941 median pay | $74,837 to $86,343 pay range |
The AAMC stipend survey also found that 96.9% of responding institutions pay the same base stipend to every resident at a given level across all specialties. In practice, that means a surgery intern and a pediatrics intern at the same hospital usually earn the same salary; pay rises with the program year, not the specialty. The weighted mean year 1 salary, which counts large programs more heavily, was $70,684. For more on resident pay, see IMA’s breakdown of how much resident doctors make.
A Sample Path From Medical School to Attending
Here is how the terms line up for a graduate who matches into a categorical internal medicine program:
- Fourth year of medical school: apply through ERAS (see IMA’s ERAS residency application guide) and rank programs in the Match.
- July, PGY-1: start as an intern under direct supervision, then progress to indirect supervision.
- Late PGY-1 or PGY-2: take USMLE Step 3 or COMLEX-USA Level 3.
- PGY-2: become a second-year resident, often supervising interns; apply for a full license once the state’s training rule is met.
- PGY-3: finish the 36-month program and become board eligible, or apply to fellowship.
A graduate headed for diagnostic radiology in the 48-month format would add one step: a preliminary or transitional PGY-1 year at one program, then four radiology years starting at PGY-2, often at a different hospital.
Pre-Med Clinical Internships Are a Different Thing
Students searching “medical internship” are often looking for clinical experience before medical school, not the PGY-1 year. These programs give undergraduates and high school students supervised time in hospitals and clinics. IMA runs pre-med internships abroad where interns, under the supervision of licensed clinicians, take part in patient care such as vital signs, patient intake and basic patient interviews, along with ward rounds and community outreach. They do not diagnose, prescribe or perform invasive procedures. How these hours count on AMCAS is each medical school’s decision, but the experience gives applicants a first look at the hospital teams they will later join as interns.
Frequently Asked Questions
Is an intern the same as a resident?
Yes. An intern is a first-year resident, also called a PGY-1. The intern year is the first 12 months of residency, and after it the doctor is called a second-year resident, or PGY-2.
Is internship required before residency?
There is no separate internship before residency in U.S. training. The intern year is part of residency. In specialties that start at PGY-2, such as many diagnostic radiology and anesthesiology programs, the applicant completes a preliminary or transitional PGY-1 year first and then joins the advanced program.
How long is a medical internship?
A medical internship lasts 12 months. ACGME requires a transitional year to be 12 months long, and a categorical intern year is the first 12 months of a longer residency, such as the 36 months required for internal medicine.
Do interns get paid less than residents?
Interns earn the program year 1 stipend, which is the lowest level. The AAMC reported a mean program year 1 salary of $68,166 as of July 1, 2025, compared with $70,499 pay in year 2 and $73,301 pay in year 3.
Can you practice medicine after an intern year?
Some state boards license U.S. graduates after one year of accredited postgraduate training. New York, for example, requires at least one year for graduates of LCME- or AOA-accredited schools. Most doctors still finish a full residency because board certification and most hospital jobs require it.
What is the difference between a preliminary year and a transitional year?
A preliminary year is one year of training inside a specialty department, usually medicine or surgery. A transitional year is a separate ACGME-accredited 12-month program that rotates through several fields, with at least 24 weeks of fundamental clinical skills rotations and at least four weeks of emergency medicine.
Are pre-med medical internships the same as a residency internship?
No. Pre-med clinical internships are experience programs for students before medical school. The residency internship is paid physician training that starts only after earning an MD or DO and matching. Students can explore supervised clinical experience through IMA’s medical internships.
