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 will vary, but will not exceed 40. The total number of items on the overall examination form will not exceed 280.
If you have a medical need for an item during your USMLE administration, a list of approved personal items is available.
Step 1 consists of multiple-choice questions prepared by examination committees composed of faculty members, teachers, 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.
The test 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.
Step 1 is constructed from an integrated content outline that organizes basic science 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.
Content Outline and Specifications
The USMLE Content Outline provides a common organization of content across all USMLE examinations. In addition, the USMLE Physician Tasks/Competencies, outline lists tasks and competencies assessed throughout the sequence of USMLE.
The USMLE Content Outline 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.
Sections focusing on individual organ systems are subdivided according to normal and abnormal processes, including principles of therapy. Each Step 1 examination covers content related to the following traditionally defined disciplines:
- behavioral sciences
- biostatistics and epidemiology
The Step 1 examination also covers content related to the following interdisciplinary areas:
- molecular and cell biology
Step 1 classifies test items along two dimensions, system and process, as shown in Table 1 below.
While not all topics listed in the content outline are included in every USMLE examination, overall content coverage is comparable in the various examination forms that will be taken by different examinees for each Step.
Most organ systems are partitioned into Normal Processes and Abnormal Processes, and include subcategories of specific disease processes. In most instances, knowledge of normal processes is evaluated in the context of a disease process or specific pathology.
The content outline 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. Broadly based learning that establishes a strong general understanding of concepts and principles in the basic sciences is the best preparation for the examination.
Step 1 Test Specifications Table 1: USMLE Step 1 Test Specifications*
Blood & Lymphoreticular System
Nervous System & Special Senses
Skin & Subcutaneous Tissue
Renal & Urinary System
Pregnancy, Childbirth, & the Puerperium
Female Reproductive & Breast
Biostatistics & Epidemiology
In addition to being organized by organ systems, the Step 1 exam is organized by physician task and competency, as shown below. More information about the physician task and competency outline is available on the USMLE Web site (http://www.usmle.org/pdfs/tcom.pdf).
Test items are constructed to assess one of the competencies listed below.
Table 2. USMLE Step 1 Specifications: Physician Task/Competencies*
- History/Physical Examination
- Laboratory/Diagnostic Studies
- Health Maintenance/Disease Prevention
* Percentages are subject to change at any time. See the USMLE Web site for the most up-to-date information.
** The general principles category includes test items concerning those normal and abnormal processes that are not limited to specific organ systems. Categories for individual organ systems include test items concerning those normal and abnormal processes that are system-specific.
*** The Step 1 examination includes management questions in only the categories listed in this table. It does not include questions related to clinical interventions, mixed management, or surveillance for disease recurrence. † This category includes questions about normal structure and function that may appear in the context of an abnormal clinical presentation.
‡ Approximately 10%-15% of questions are not classified in the normal processes, abnormal processes, or principles of therapeutics categories. These questions are likely to be classified in the general principles, biostatistics/evidence-based medicine, or social sciences categories in the USMLE Content Outline.
- 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 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.
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.
The questions are prepared by examination committees composed of faculty members, teachers, 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.
A 32-year-old woman with type 1 diabetes mellitus has had progressive renal failure over the past 2 years. She has not yet started dialysis. Examination shows no abnormalities. Her hemoglobin concentration is 9 g/dL, hematocrit is 28%, and mean corpuscular volume is 94 m3. A blood smear shows normochromic, normocytic cells. Which of the following is the most likely cause?
- Acute blood loss
- Chronic lymphocytic leukemia
- Erythrocyte enzyme deficiency
- Erythropoietin deficiency
- Microangiopathic hemolysis
- Polycythemia vera
- Sickle cell disease
- Sideroblastic anemia
- β-Thalassemia trait