Internal medicine residency is 36 months, or three years. That’s the standard set by the Accreditation Council for Graduate Medical Education (ACGME) for all accredited programs in the United States. Those three years begin after four years of medical school, meaning most internists complete at least seven years of training after college before practicing independently.
What the Three Years Look Like
The 36-month program breaks down into distinct training blocks. At least 10 months must be spent in outpatient clinics, where residents manage patients with chronic conditions like diabetes, high blood pressure, and heart disease. A significant portion of the remaining time goes to inpatient hospital wards and intensive care rotations, where residents care for acutely ill patients. Programs also must build in at least six months of individualized learning, which can include electives, research time, or deeper training in a subspecialty of interest.
Your first year (called intern year or PGY-1) is the most grueling. You’re the front-line doctor writing orders, responding to pages, and managing day-to-day patient care under supervision. By your second and third years, you take on more of a supervisory role, overseeing interns while handling more complex cases and making higher-level decisions. The progression is deliberate: each year builds clinical judgment and independence.
Categorical vs. Preliminary Tracks
Not everyone who enters an internal medicine program stays for all three years. There are two distinct tracks. A “categorical” position is the full three-year program that leads to board certification in internal medicine. This is what most people mean when they talk about internal medicine residency.
A “preliminary” position lasts only one to two years. It’s designed for doctors who need foundational training in internal medicine before moving into a different specialty, like radiology, dermatology, or ophthalmology. These specialties require applicants to complete a preliminary year of broad medical training before starting their advanced program. Preliminary residents do similar clinical work during their year but aren’t on track for internal medicine board certification.
Combined Programs Take Longer
Some residency programs combine internal medicine with another specialty, leading to dual board certification. These programs are longer than a standard three-year track but shorter than completing both residencies separately. Combined emergency medicine and internal medicine, for example, runs 60 months (five years), with time split equally between the two disciplines each year. Medicine-pediatrics (Med-Peds) is another popular combination, typically lasting four years and producing doctors certified in both adult and pediatric care.
Subspecialty Fellowships Add One to Three Years
If you want to specialize further after completing internal medicine residency, you’ll need a fellowship. Cardiology, gastroenterology, oncology, pulmonary and critical care, endocrinology, rheumatology, infectious disease, and nephrology are among the most common paths. Fellowship training typically adds one to three years beyond the initial three-year residency, depending on the subspecialty. Cardiology fellowships, for instance, run three years, while endocrinology fellowships are typically two. That means a cardiologist’s total post-medical-school training stretches to six or seven years.
Working Hours and Schedule
Internal medicine residents are capped at 80 hours of clinical and educational work per week, averaged over a four-week period. That ceiling includes all hospital duties, educational activities, and any clinical work done from home. Residents must also get at least one full day off per week (averaged over four weeks) and at least 14 hours free after a 24-hour in-house call shift. Programs should also provide eight hours off between scheduled work periods.
In practice, many internal medicine residents work 60 to 70 hours during lighter outpatient rotations and push closer to the 80-hour limit during demanding inpatient or ICU blocks. The schedule typically involves a mix of daytime shifts, overnight call, and weekend coverage that rotates throughout the year.
Pay During Residency
Residents earn a salary (often called a stipend) that increases modestly each year. At UCLA, one of the larger academic medical centers, resident salaries for 2024-2025 are roughly $89,000 in PGY-1, $92,000 in PGY-2, and $95,000 in PGY-3. Rates vary by institution and region, with programs in higher cost-of-living areas generally paying more. These figures are set to rise further in 2025, with UCLA’s PGY-1 salary jumping to nearly $94,000. Most programs also include health insurance, malpractice coverage, and a small allowance for educational expenses.
Board Certification Timeline
To sit for the American Board of Internal Medicine (ABIM) certification exam, you must complete all 36 calendar months of training, including vacation time, by August 31 of the exam year. Of those 36 months, at least 30 must be spent in general internal medicine, subspecialty internal medicine, or emergency medicine. Up to three months can go toward electives approved by your program director, and up to three months count as vacation.
Programs have some flexibility for minor training gaps. If you fall short by 35 days or less due to illness, parental leave, or other circumstances, the ABIM lets your program director decide whether you’ve met the competency requirements without requiring you to make up the time. Longer absences generally require additional training before you’re eligible to take the exam.