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Bulletin of Information

The USMLE Bulletin of Information is a compilation of all the facts and details about the USMLE. Before you apply for any of the three steps of the USMLE, you must become familiar with the bulletin.

Step 1 assesses whether you understand and can apply important concepts of the sciences basic to the practice of medicine, with special emphasis on principles and mechanisms underlying health, disease, and modes of therapy. Step 1 ensures mastery of not only the sciences that provide a foundation for the safe and competent practice of medicine in the present, but also the scientific principles required for maintenance of competence through lifelong learning. Step 1 is constructed according to an integrated content outline that organizes basic science material along two dimensions: system and process.

Step 1 is a one-day examination. It is divided into seven 60-minute blocks and administered in one 8-hour testing session. The number of questions per block on a given examination form may vary, but will not exceed 40. The total number of items on the overall examination form will not exceed 280.

Practice materials, which include Sample Test Items (PDF) and web-based Tutorial and Practice Test Items, as well as other informational materials, are available at the USMLE website. Examinees must also read the USMLE Bulletin of Information.


  • The term item is used to describe a test question in any format.
  • You must run the web-based Tutorial and Practice Test Items to become familiar with the test software prior to your test date.
  • The tutorial provided at the beginning of the Step 1 Examination has fewer screens and less detailed information than the Step 1 web-based Tutorial and Practice Test Items accessed from the USMLE website.
  • The web-based Tutorial and Practice Test Items on the USMLE website include items with associated audio findings. Become familiar with how these types of test items function before your test date.

Please visit the USMLE website often to view announcements, regarding changes in the test delivery software, and to access updated practice materials. You must obtain the most recent information before taking any USMLE examination.

Content Description

Step 1 consists of multiple-choice questions (MCQs), also known as items, created by USMLE committees composed of faculty members, investigators, and clinicians with recognized prominence in their respective fields. Committee members are selected to provide broad representation from the academic, practice, and licensing communities across the United States and Canada.

Step 1 is designed to measure basic science knowledge. Some questions test the examinee's fund of information per se, but the majority of questions require the examinee to interpret graphic and tabular material, to identify gross and microscopic pathologic and normal specimens, and to solve problems through application of basic science principles.

The content description is not intended as a curriculum development or study guide. It provides a flexible structure for test construction that can readily accommodate new topics, emerging content domains, and shifts in emphasis. The categorizations and content coverage are subject to change.

Broad-based learning that establishes a strong general understanding of concepts and principles in the basic sciences is the best preparation for the examination.

NOTE: What new content appeared on Step 1 exams administered after the exam was updated in October 2020?

No new content was assessed in Step 1 exams administered after the exam was updated in October 2020. Examinees testing after the October 2020 update saw an increase in the number of items that assess knowledge of Communication and Interpersonal Skills; this content has been included on the Step 1 exam for many years.

You can see a representative Step 1 item assessing knowledge of Communication and Interpersonal Skills here.

Content Outline

All USMLE examinations are constructed from an integrated content outline, which organizes content according to general principles and individual organ systems. Test questions are classified in one of 18 major areas, depending on whether they focus on concepts and principles that are important across organ systems or within individual organ systems.

Step 1 content weighting for these topics is provided in Table 1 below. Sections focusing on individual organ systems are subdivided according to normal and abnormal processes, including mechanisms of pharmacotherapy. In most instances, knowledge of normal processes is evaluated in the context of a disease process or specific pathology.

While not all topics listed in the content outline are included in each USMLE Step examination, overall content coverage is comparable among the various examination forms that will be taken by different examinees for each Step.

Table 1: Step 1 Test Specifications*

System Range, %
General Principles** 12–16
Blood & Lymphoreticular/Immune Systems 7–11
Behavioral Health & Nervous Systems/Special Senses 9–13
Musculoskeletal, Skin & Subcutaneous Tissue 6–10
Cardiovascular System 5–9
Respiratory & Renal/Urinary Systems 9–13
Gastrointestinal System 5–9
Reproductive & Endocrine Systems 9–13
Multisystem Processes & Disorders 6–10
Biostatistics & Epidemiology/Population Health 4–6
Social Sciences: Communication and Interpersonal Skills 6–9

* Percentages are subject to change at any time.
** The Step 1 General Principles category includes normal and abnormal processes that are not limited to specific organ systems.

Physician Tasks/Competencies

An additional organizing construct for Step 1 design is physician tasks and competencies. Each test question is constructed to assess one of the competencies listed in Table 2. Click here for detailed information about the physician tasks and competencies outline.

Table 2: Step 1 Physician Tasks/Competencies Specifications*

Competency Range, %
Medical Knowledge: Applying Foundational Science Concepts 60–70
Patient Care: Diagnosis 20–25
Patient Care: Management 0**
Communication and Interpersonal Skills 6–9
Practice–based Learning & Improvement 4–6

* Percentages are subject to change at any time.
** Test items related to management are covered in Step 2 CK and Step 3 examinations.


Each Step 1 examination covers content related to traditionally defined disciplines and interdisciplinary areas as listed in Table 3.

Table 3: Step 1 Discipline Specifications*

System Range, %
Pathology 44–52
Physiology 25–35
Pharmacology 15–22
Biochemistry & Nutrition 14–24
Microbiology 10–15
Immunology 6–11
Gross Anatomy & Embryology 11–15
Histology & Cell Biology 8–13
Behavioral Sciences 8–13
Genetics 5–9

* Percentages are subject to change at any time.

More than 100 sample Step 1 test questions are available in both PDF format and as an interactive testing experience.

Below are examples of different types of competencies tested on the Step 1 examination.

Example Question: Pharmacology: Foundational Science

The Step 1 examination continues to assess content related to the discipline of pharmacology. However, the primary focus of this content will be on the mechanisms of actions of drugs rather than on specific pharmacotherapy, drug-drug interactions, adverse effects, or contraindications of medications.

A 27-year-old woman comes to the office for counseling prior to conception. She states that a friend recently delivered a newborn with a neural tube defect and she wants to decrease her risk for having a child with this condition. She has no history of major medical illness and takes no medications. Physical examination shows no abnormalities. It is most appropriate to recommend that this patient begin supplementation with a vitamin that is a cofactor in which of the following processes?

  • Biosynthesis of nucleotides
  • Protein gamma glutamate carboxylation
  • Scavenging of free radicals
  • Transketolation
  • Triglyceride lipolysis

(Answer: A)

Example Question: Biostatistics

The Step 1 examination includes items pertaining to the understanding of the principles of biostatistics and epidemiology, including principles of research ethics and regulatory issues.

A study is designed to evaluate the feasibility of acupuncture in children with chronic headaches. Sixty children with chronic headaches are recruited for the study. In addition to their usual therapy, all children are treated with acupuncture three times a week for 2 months. Which of the following best describes this study design?

  • Case-control
  • Case series
  • Crossover
  • Cross-sectional
  • Historical cohort
  • Randomized clinical trial

(Answer: B)

Example Question: Communications

The Step 1 examination assesses communication and interpersonal skills, including those needed to foster relationships with patients and families, gather information to provide patient care, provide information to patients and families regarding diagnosis and treatment, help patients and families make medical decisions, and support the emotions of patients and families. Use of an interpreter or surrogate appropriately will also be assessed.

A 26-year-old woman comes to the physician with her husband for counseling prior to conception. Her mother and three of her five siblings have type 2 diabetes mellitus. She is 170 cm (5 ft 7 in) tall and weighs 82 kg (180 lb); BMI is 28 kg/m2. Her blood pressure is 148/84 mm Hg. Physical examination shows no other abnormalities. Her fasting serum glucose concentration is 110 mg/dL. Which of the following is the most appropriate initial statement by the physician?

  • "Let’s review ways you can optimize your own health before conceiving."
  • "We should test you for islet cell antibodies before you try to conceive."
  • "You can conceive right away since you are in good health."
  • "You should avoid gaining weight during pregnancy because you are already overweight and at risk for type 2 diabetes mellitus."
  • "You should have no problems with your pregnancy if you start insulin therapy."

(Answer: A)


  • Read each question carefully. It is important to understand what is being asked.
  • Try to generate an answer and then look for it in the response option list.
  • Alternatively, read each option carefully, eliminating those that are clearly incorrect.
  • Of the remaining options, select the one that is most correct.
  • If unsure about an answer, it is better to guess since unanswered questions are automatically counted as wrong answers.

Single-Best-Answer Questions

A single patient-centered vignette is associated with one question followed by four or more response options. The response options are lettered (ie, A, B, C, D, E). A portion of the questions involves interpretation of graphic or pictorial materials. You are required to select the best answer to the question. Other options may be partially correct, but there is only ONE BEST answer. This is the traditional, most frequently used multiple-choice question format on the examination.

Example Single-Best-Answer Question

A 22-year-old woman is brought to the emergency department by ambulance 30 minutes after she was struck by an oncoming motor vehicle while bicycling. The paramedics report that the patient sustained substantial blood loss at the scene. On arrival, she appears anxious, pale, and diaphoretic. Her pulse is 140/min, respirations are 24/min, and blood pressure is 88/46 mm Hg. Physical examination shows numerous abrasions and a 12-cm laceration on the anterior portion of the right thigh, which was bandaged at the scene but is now saturated with blood. Cardiopulmonary and abdominal examinations show no abnormalities. Compared with a healthy person, which of the following sets of findings is most likely in this patient?

Mixed Venous
O2 Saturation
Systemic Peripheral
Vascular Resistance
Urine Flow
A. No change
B. No change
C. No change No change
D. No change No change No change
F. No change

(Answer: E)