Hundreds of practice questions mapped to all organ systems and foundational science disciplines on the USMLE Step 1. Questions include worked explanations with full solution steps.
Every question is stress-tested by competing AI systems before it is published.
Start practicing for freeSelect an answer to check yourself. Sign up to access the full question bank with worked solutions.
A 14-year-old boy is significantly shorter than his peers and has not begun puberty. His father was a "late bloomer." Exam shows Tanner stage 1 with bone age of 11.5 years. Growth velocity is 5 cm/year. TSH, IGF-1, and CBC are normal. Which of the following is the most likely diagnosis?
A 14-month-old boy is not walking yet. He sat without support at 6 months, crawled at 10 months, stands holding furniture, uses a pincer grasp, and waves bye-bye. No dysmorphic features. Growth is at the 50th percentile. The most likely explanation is:
A 15-month-old boy's diet consists primarily of cow's milk (4–5 cups daily) and crackers. He has pale conjunctivae. Labs: Hb 8.2 g/dL, MCV 68 fL, serum iron 25 μg/dL, TIBC 450 μg/dL, ferritin 8 ng/mL. The most likely explanation is:
Those were just samples. Sign up to access hundreds more with full worked solutions.
Continue practicing for freeUnited States Medical Licensing Examination — Step 1 is a CBT exam of 280 questions over 8h.
18 practice areas in the USMLE Step 1 question bank, each with its own questions and analytics.
Every question in the bank is written in one of these formats.
USMLE Step 1 is the first of the three United States Medical Licensing Examinations, co-sponsored by the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). It tests whether you can apply the basic sciences (pathology, physiology, pharmacology, biochemistry, microbiology, immunology, anatomy, and the behavioral and social sciences) to clinical vignettes. Most MD students take it at the end of the preclinical years. Students at osteopathic schools may take it alongside COMLEX Level 1, and international medical graduates take it on the way to ECFMG certification.
Since January 2022 Step 1 has been reported as pass/fail only. That change moved the weight of residency selection onto Step 2 CK, but it did not make Step 1 easier. The exam still runs up to 280 questions over a full day, and a failed attempt stays on your USMLE transcript. The practice bank on this page is organized by the same organ systems and disciplines as the USMLE content outline, so that you can drill the specific system-discipline combinations where your accuracy is weakest.
Source: USMLE Step 1 Content Description and General Information
| System or discipline | What it covers |
|---|---|
| Anatomy | Gross anatomy, embryology, and histology as they explain clinical presentations and imaging findings |
| Behavioral Sciences | Psychiatry fundamentals, substance use, sleep, learning, and physician-patient communication |
| Biochemistry | Metabolism, enzyme kinetics, molecular biology, genetics, nutrition, and inborn errors of metabolism |
| Biostatistics and Epidemiology | Study design, bias, sensitivity and specificity, predictive values, risk measures, and interpreting results |
| Cardiovascular System | Cardiac and vascular physiology, pathology, pharmacology, and congenital heart disease |
| Endocrine System | Hormone synthesis and regulation, endocrine pathology, diabetes, thyroid, adrenal, and pituitary disorders |
| Gastrointestinal System | GI and hepatobiliary physiology, pathology, infections, and pharmacology |
| Hematologic and Lymphoreticular System | Anemias, coagulation, hematologic malignancies, transfusion, and lymphoid disorders |
| Immune System | Innate and adaptive immunity, hypersensitivity, immunodeficiency, transplantation, and immunopharmacology |
| Microbiology | Bacteriology, virology, mycology, parasitology, antimicrobials, and vaccine principles |
| Musculoskeletal System | Bone, joint, muscle, and connective tissue physiology and pathology, including rheumatology |
| Nervous System | Neuroanatomy, neurophysiology, neuropathology, neuropharmacology, and special senses |
| Pathology | General principles of cell injury, inflammation, neoplasia, and organ-system pathology |
| Pharmacology | Pharmacokinetics, pharmacodynamics, autonomic drugs, toxicology, and drug classes across systems |
| Renal and Urinary System | Renal physiology, acid-base, electrolytes, glomerular and tubular disease, and diuretics |
| Reproductive System | Reproductive physiology, pregnancy, gynecologic and male reproductive pathology, and hormones |
| Respiratory System | Ventilation and gas exchange, obstructive and restrictive disease, infections, and lung cancer |
| Skin and Subcutaneous Tissue | Dermatologic pathology, skin infections, blistering diseases, and cutaneous malignancy |
The USMLE content outline classifies every item along two axes at once, an organ system and a discipline or competency, and publishes approximate percentage ranges for each axis in the official content description. Because the axes overlap, those ranges are not reproduced here. Download the current outline from usmle.org and use it alongside this table. General principles of foundational science and multisystem processes are tested across the system-specific areas listed above.
Step 1 is reported as pass or fail. Examinations taken on or after January 26, 2022 do not report a three-digit score to you or to your school, and residency programs never see one either. The minimum passing standard is set by the USMLE Composite Committee and reviewed periodically. All that appears on your transcript is the outcome and the date. Examinees who fail receive a performance profile showing relative strengths and weaknesses by content area, which is the primary planning tool for a retake.
Every item is a single-best-answer multiple-choice question. Many are built around a clinical vignette with laboratory values or an image, and occasionally with audio or video. The normal laboratory values reference is available on screen. There is no penalty for wrong answers. Some items on every form are unscored pretest items that are indistinguishable from scored ones, and once you exit a block you cannot return to it, so answer everything before the block clock runs out.
Most U.S. students finish coursework and then take a dedicated study period of roughly six to eight weeks before Step 1. The plan below assumes seven weeks at 50 to 60 hours a week, with questions as the primary learning tool from the first day instead of a reward saved for the end.
Step 1 vignettes are built by item writers who know exactly which wrong answer a half-prepared student will reach for: the drug that treats the disease when the stem asked for its mechanism, the diagnosis that matches the buzzword but not the time course, the enzyme one step upstream of the one that is actually deficient, the "true" statement about the condition that does not answer the question asked. Every Step 1 question on PassExams is written the same way, and when you miss one you see why the option you picked was wrong and what separates it from the correct answer, instead of a paragraph about the right one. On Pro, each wrong option also carries its trap label: misread stem, misconception, scope confusion, or a partial answer that stops one link short of the mechanism.
Over hundreds of items those labels turn into a pattern you cannot see from inside a single block. Perhaps your Renal misses are almost all acid-base misconceptions while your Pharmacology misses are stem misreads where you answered "which drug" when the item asked "which side effect". The variant engine then writes fresh vignettes that test the same mechanism from a different presentation until the gap closes, and hints eliminate the most tempting distractor and push you back to the causal chain without handing you the answer. What you want walking into Prometric is the mechanism instead of a memorized association.
Begin questions on the first day of your dedicated period and let the misses set your reading list. Push every review to the mechanism so that each item ends with a one-line reason the correct option follows from the stem, and give the same attention to answers you reached by luck. Rehearse full-length days in fourteen 30-minute blocks of up to 20 items, the format for exams on or after May 14, 2026. Pass/fail reporting did not lower the standard, and a failed attempt stays on your USMLE transcript.
Up to 280 single-best-answer multiple-choice questions. For exams on or after May 14, 2026 they are delivered in fourteen 30-minute blocks of up to 20 items each. The exact number varies slightly between forms, and some items are unscored pretest questions.
One 8-hour testing day: seven hours of question blocks (fourteen 30-minute blocks), a minimum of 55 minutes of break time, and an optional 5-minute tutorial whose time is added to your breaks if you skip it. Finishing a block early also adds to your break allowance.
Since January 2026, students and graduates of LCME- or COCA-accredited U.S. medical schools apply through NBME on the MyUSMLE portal, and students and graduates of medical schools outside the United States apply through the FSMB USMLE portal. ECFMG no longer handles registration, although ECFMG Certification eligibility remains a requirement for international candidates.
Yes. For exams taken on or after January 26, 2022, Step 1 results are reported only as pass or fail. No three-digit score is released to you or your school, and residency programs do not receive one.
USMLE sets a minimum passing standard and reviews it periodically. It rose from 194 to 196 on January 26, 2022, the same day pass/fail reporting began. Because results are reported as pass or fail, no numeric score is shown on your report. The practical target is consistent, comfortable accuracy on timed practice blocks and self-assessments instead of a specific number.
Most U.S. MD students take it after the preclinical curriculum, typically at the end of the second year after a dedicated study period of about six to eight weeks. Some curricula schedule it after core clerkships instead. Osteopathic students sit COMLEX Level 1 and may take Step 1 in addition.
Four attempts is the maximum, and incomplete attempts count. You may not take it more than three times in a 12-month period, and a fourth attempt must be at least 12 months after the first and 6 months after the most recent. Once you pass a Step you cannot retake it.
No. Step 1 and Step 2 CK may be taken in either order. Step 3 requires that both Step 1 and Step 2 CK have been passed.
The preclinical curriculum is the bulk of the preparation. The dedicated period on top of it is usually six to eight weeks of full-time study. Students who kept up with questions and spaced repetition during coursework need less. Students studying alongside clerkships or work should plan for more calendar time at fewer hours per week.
Daily practice questions are free. Upgrade for the full question bank and AI study tools.
Create a free accountNo credit card required
10% of our revenue funds free and discounted access for those who need it most.