5.0The internal medicine shelf is the NBME Medicine Subject Exam: 110 questions in 2 hours 45 minutes on NBME's timing chart, set on the wards and in the emergency department. It is usually the broadest shelf you will sit, because almost every organ system appears and older adults make up a large share of the patients.
Internal medicine is also the clerkship that maps most closely onto Step 2 CK and COMLEX Level 2-CE. Time spent learning to work up a medicine patient pays off on both, which is why we treat this shelf as the backbone of third-year studying rather than a one-off test.
The medicine shelf at a glance
| Topic | Official rule | Source |
|---|---|---|
| Length | 2 hours 45 minutes of testing; a web tutorial adds 15 minutes. | NBME subject exam timing chart |
| Questions | 110. Some may be unscored field-test questions. | NBME subject exam timing chart |
| Scoring | Equated Percent Correct (EPC) on a 0 to 100% scale: the share of the content you have mastered. | NBME Subject Exam Program Guide |
| Passing score | NBME sets none. Your school sets pass and honors cut-offs, with help from NBME grading guidelines that are reviewed every two to three years. | NBME Subject Exam Program Guide |
| Results | Often posted to your school the day after the testing window ends; can take up to three business days. | NBME Subject Exam Program Guide |
| Who registers | Your school. NBME sells subject exams to medical school faculty only. | NBME: subject exam questions |
| Official practice | Clinical Science Mastery Series, Medicine: 50 questions per form, $21, with a table that converts your result to the subject exam scale. | NBME: Clinical Science Mastery Series |
What medicine shelf questions look like
A typical medicine question gives you a full admission: history, vitals, exam, a table of labs and sometimes an ECG or chest film, then asks for the most likely diagnosis or the next step. The trap is usually in the vitals or one abnormal lab you read past.
Management questions often hinge on timing: what you do in the first hour for an unstable patient is different from what you do on day three. Older patients bring a second layer, because a drug that is fine at forty may be the cause of the fall or the confusion at eighty.
What the Internal Medicine shelf covers
The ranges below are NBME's, from its current Internal Medicine subject exam outline (NBME outline, checked November 1, 2026).
| By system | Share of exam |
|---|---|
| Cardiovascular system | 10–15% |
| Multisystem processes and disorders | 10–15% |
| Blood and lymphoreticular system | 5–10% |
| Respiratory system | 5–10% |
| Gastrointestinal system | 5–10% |
| Renal and urinary system | 5–10% |
| Endocrine system | 5–10% |
| General principles, including normal age-related findings and care of the well patient | 1–5% |
| Immune system | 1–5% |
| Behavioral health | 1–5% |
| Nervous system and special senses | 1–5% |
| Skin and subcutaneous tissue | 1–5% |
| Musculoskeletal system | 1–5% |
| Female reproductive system and breast | 1–5% |
| Male reproductive system | 1–5% |
| Biostatistics, epidemiology/population health and interpretation of the medical literature | 1–5% |
| Social sciences, including medical ethics and jurisprudence | 1–5% |
| By physician task | Share of exam |
|---|---|
| Diagnosis: history, exam, diagnostic studies and patient outcomes | 45–50% |
| Health maintenance, pharmacotherapy, intervention and management | 25–30% |
| Applying foundational science concepts | 15–20% |
By site of care, NBME sets ambulatory questions at 35–40%, inpatient at 40–45% and the emergency department at 20–25%. By age, patients 18 to 65 make up 60–65% of questions and patients 66 and older 35–40%, a bigger older-adult share than most shelves.
High-yield areas on the medicine shelf
These follow directly from the weights above. Cardiovascular disease and multisystem processes carry the most questions, then blood, respiratory, digestive, renal and endocrine disease, so they get the most of your time:
- Cardiology: chest pain and acute coronary syndromes, heart failure, atrial fibrillation and anticoagulation decisions, valve disease and endocarditis.
- Across systems: sepsis and common infections, fluid, electrolyte and acid-base problems, and how one disease spills into several organs.
- Pulmonary: pneumonia, asthma and COPD exacerbations, pulmonary embolism, and reading a blood gas.
- Renal: acute kidney injury, chronic kidney disease, sodium and potassium disorders.
- GI and liver: GI bleeding, cirrhosis and its complications, pancreatitis.
- Endocrine: diabetes and its emergencies, thyroid and adrenal disease.
- Hematology: anemia work-ups, thrombocytopenia, clotting and bleeding problems.
- Older adults: polypharmacy, falls, delirium and goals-of-care conversations, given the 35–40% share of patients 66 and older.
A closer look at the biggest systems
Cardiovascular disease. Most cardiology questions are really decisions: which chest pain needs a catheterisation lab now, which atrial fibrillation patient needs anticoagulation, which heart failure patient needs a diuretic versus a different drug class. Learn the decision points rather than lists of findings.
Respiratory and digestive disease. Each is 5–10% of the exam. Questions often start in one organ and end in another, such as a pneumonia that becomes septic shock with kidney injury, or a GI bleed in a patient on anticoagulation. Practise following a patient across systems instead of studying each organ alone.
Common mistakes on the medicine shelf
- Jumping to treatment when the question asks for the next diagnostic step. Diagnosis is 45–50% of this exam, and management 25–30%.
- Skimming the vital signs. An unstable patient changes the right answer, almost always toward stabilising first.
- Studying cardiology and ignoring the "small" systems. Five areas sit at 5–10% each, and together they outweigh any single system.
- Memorising drug names without the reason to stop or switch one, which is how pharmacotherapy questions are usually written.
- Treating biostatistics and ethics as free points. They are small but they show up, and they are easy to lose on a tired afternoon.
Test-day tips for the medicine shelf
- Read the last line of the question first so you know whether it wants a diagnosis or a next step.
- Scan the vitals before the history; instability changes the answer.
- Use the lab table actively: find the one abnormal value the vignette was written around.
- Keep an eye on the clock in the second half, when long vignettes slow you down.
How to study for the internal medicine shelf during the rotation
Medicine rotations are long days with a lot of reading built in, so the plan has to use the patients you are already seeing. We tie each night of questions to the conditions on your team list, so a heart failure admission becomes a heart failure question block that evening.
Early in the rotation we build broad coverage across all the systems. In the second half we move to timed mixed blocks and full practice forms, and we use your results to decide which systems get the last week. If the exam is close and your practice scores are not where they need to be, we change the plan rather than adding hours.
A sample week of medicine shelf prep with us
- Monday: 30-minute session to set the week from your team list: say, two heart failure patients and a GI bleed.
- Tuesday to Thursday: timed question blocks on those systems each evening, with misses tagged by system.
- Friday: session to review the misses and fix the reasoning, not just the fact.
- Weekend: one mixed block across every system, so nothing goes cold.
Session lengths and the number of blocks change with your schedule; the structure stays the same.
A sample 8-week internal medicine clerkship schedule
Sample schedule
Sample schedule for illustration only. Not a real student, not real data. Your tutor builds your actual plan around your practice-exam results and the time you have.
Sample 8-week Internal Medicine clerkship shelf schedule: 8 weeks, about 2 hours a day, 6 days a week. One day off each week.
A typical day
| Block | Hours | What |
|---|---|---|
| Question bank | 1 | 20 questions after clinical duties, full review |
| Anki review | 0.5 | Due reviews |
| Content review | 0.5 | Read on your own patients’ conditions |
Week by week
| Week | Focus | Practice exam |
|---|---|---|
| Week 1 | Cardiovascular | |
| Week 2 | Respiratory | |
| Week 3 | GI | |
| Week 4 | Renal / Urinary | NBME Clinical Science Mastery Series, Medicine |
| Week 5 | Endocrine | |
| Week 6 | Heme / Onc; Immune / ID | |
| Week 7 | Weakest areas from self-assessment | NBME Clinical Science Mastery Series, Medicine |
| Week 8 | Mixed timed blocks; Shelf exam (110 questions, 2 hours 45 minutes) |
NBME Clinical Science Mastery Series self-assessment (50 questions, $21) in weeks 4 and 7; its conversion table maps to the shelf score scale.
The week-by-week order follows the outline weights: the two 10–15% systems come first, so a mid-rotation self-assessment can tell you what to fix in weeks 7 and 8. If your rotation is shorter than eight weeks, keep weeks 1, 2, 3, 7 and 8 and fold the rest into mixed blocks.
After each medicine practice form, ask
- Which systems did I miss most, and are they the 10–15% systems or the 5–10% ones?
- Did I miss diagnosis questions or management questions?
- How many misses came from an unstable patient I treated as stable?
- Did older patients trip me up on drugs or goals of care?
- Was I out of time at the end of a block?
Where the medicine shelf leads
Medicine is the rotation that feeds Step 2 CK and COMLEX Level 2-CE most directly. On NBOME's Level 2-CE blueprint, circulatory and hematologic systems, respiratory and gastrointestinal presentations are each set at a minimum of 10%, the same organ systems that dominate this shelf.
Keep your medicine question notes after the rotation. They become the core of your Step 2 CK or Level 2-CE review, and the habits you build here, reading vitals first and choosing the next diagnostic step, carry straight over.
Study resources for the medicine shelf
For medicine, NBME's Clinical Science Mastery Series offers 50-question practice forms at $21 each. Take one early as a baseline and save the rest for the last two weeks, when the conversion table tells you roughly where you would land on the real exam.
Pair those with a clinical question bank you work every night, your clerkship's own reading list, and an Anki deck tuned to the topics above. Your attending's teaching points from rounds are worth writing down: they are usually the same pearls the exam tests.
Who tutors the medicine shelf
This shelf is led by Dr. Shauhin “Sean” Moazezi, DO, a board-certified internist, so this is his home ground. Dr. David Wadie, DO is a cardiology fellow and board-certified internist, which matters on an exam where cardiovascular disease is the single largest system.
A student on rotations and boards with us
“…He helped me make a plan, pass on my first attempt, got me then through all my clinical rotations to pass my Shelf exams on the first try, got me a good Step 2 score, coached me on my Interview season (where I got a good amount…”
— Tim S
“Their approach to NBME style questions helped me reverse some detrimental testing habits and optimize my fund of knowledge. They are experts at STEP 2 and got me through it after I had a difficult time passing shelf exams this year.”
Sara Z.
One-on-one Internal Medicine shelf tutoring with The Boards Professor costs $349 per 50-minute session, online by live video (Zoom or Google Meet). Read how shelf exam tutoring works, or book a free intro consult.