What Is the USMLE Step 1 Exam? Format, Scoring and How to Prepare (2026)

USMLE stands for the United States Medical Licensing Examination. Every medical graduate, from the US or abroad, must pass it to get a license to practice medicine in the United States. It has three steps: Step 1, Step 2 CK (Clinical Knowledge) and Step 3. This guide explains what Step 1 tests, how the exam day works, how it is scored, and how to prepare.

What does USMLE Step 1 test?

Step 1 tests whether you understand and can apply the basic sciences to the practice of medicine: the principles of health, the mechanisms of disease, and how treatments work. Most questions are clinical vignettes, so you must use basic science knowledge to solve a patient problem rather than recall isolated facts.

According to the official content outline, the largest disciplines are:

• Pathology: about 45–55% of questions
• Physiology: about 30–40%
• Pharmacology and microbiology: about 10–20% each
• Anatomy, biochemistry, immunology, genetics, histology and behavioral sciences make up the rest.

Questions on communication, ethics and biostatistics also appear. (A question can count toward more than one discipline, so the percentages add up to more than 100%.) See the official Step 1 content outline for details.

Step 1 exam format

Step 1 is a one-day, 8-hour computer-based exam. Since May 14, 2026, the format is:

• 14 blocks of 30 minutes each
• Up to 20 questions per block (no more than 280 questions in total)
• At least 55 minutes of break time, plus an optional 5-minute tutorial; finishing a block early adds to your break time

Before May 14, 2026, the exam had seven 60-minute blocks of up to 40 questions. Older study guides may still describe that format.

How is Step 1 scored?

Since January 2022, Step 1 is pass/fail only. You no longer receive a three-digit score. This means residency programs look more closely at your Step 2 CK score, clinical experience and letters, but you still must pass Step 1 to continue.

Who is eligible to take Step 1?

• US and Canadian students and graduates of MD or DO programs register through the NBME.
• International medical students and graduates register through the ECFMG. Your medical school must be listed in the World Directory of Medical Schools with an ECFMG note.

Check the current USMLE Bulletin of Information for exact rules, fees and attempt limits, which can change.

Where do you take the exam?

Step 1 is given at Prometric test centers in the United States and many other countries. After your registration is approved, you receive a scheduling permit and choose your date at Prometric. Read the test-day rules carefully: bring a valid, unexpired government ID that matches your registration name exactly.

How to prepare for Step 1

1. Build your foundation with a review book, organized by organ system.
2. Do as many practice questions as you can. Question banks such as UWorld and AMBOSS use the same vignette style as the real exam. Read every explanation, including why the wrong answers are wrong.
3. Take NBME self-assessments to check whether you are ready.
4. Start with free questions: try the free official practice materials at USMLE.org, and our own free Step 1 questions with explanations.

Free Step 1 practice questions on this site

• Pharmacology: quinidine, metoclopramide and buspirone
• Pathology: Boerhaave syndrome, Hodgkin lymphoma and glioblastoma
• Slipped capital femoral epiphysis and childhood hip disorders
• More questions on QBank USMLE

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Written by Dr. Ray Makar, MD, who passed the USMLE as an international medical graduate. Last updated: October 2026. Exam rules change; always confirm details at USMLE.org.

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