Step 2 One-day examination

Step 2 CK assesses an examinee’s ability to apply medical knowledge, skills, and understanding of clinical science essential for the provision of patient care under supervision and includes emphasis on health promotion and disease prevention. Step 2 CK ensures that due attention is devoted to principles of clinical sciences and basic patient-centered skills that provide the foundation for the safe and competent practice of medicine under supervision.

Step 2 CK is a one-day examination. It is divided into eight 60-minute blocks and administered in one 9-hour testing session. The number of questions per block on a given examination will vary but will not exceed 40. The total number of items on the overall examination will not exceed 318.

The examination also includes a minimum allotment of 45 minutes of break time and a 15-minute optional tutorial. The amount of time available for breaks may be increased by finishing a block of test items or the optional tutorial before the allotted time expires.

Practice materials, which include Sample Test Items (PDF) and simulated web-based Tutorial and Practice Test Items, tutorials, 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 2 CK Examination has fewer screens and less detailed information than the Step 2 CK web-based Tutorial and Practice Test Items on the USMLE website.
  • The web-based Tutorial and Practice Test Items on USMLE website include single multiple-choice questions, a sequential set of multiple-choice questions, a scientific abstract (a summary of an experiment or clinical investigation, accompanied by two or more questions), and items with audio or video findings.

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

All USMLE examinations are constructed from an integrated content outline. Content is organized according to general principles and individual organ systems. Test questions are classified into one of 18 major categories, depending on whether they focus on concepts and principles that are applicable across organ systems or within individual organ systems. Most organ systems are subdivided into normal and abnormal processes. They 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. Sections focusing on individual organ systems are subdivided according to normal and abnormal processes, including principles of therapy.

Not all topics listed in the content outline are included in every USMLE examination. Overall content coverage is comparable in the various examinations that will be administered to different examinees for each Step. The Step 2 CK examination covers content of specific disease processes or pathology. The Step 2 CK systems specifications are listed in Table 1.

Table 1: Step 2 CK Test Specifications*

System Range %
General Principles of Foundational Science** 1-3
Immune Systems 4-6
Blood & Lymphoreticular System 4-7
Behavioral Health 6-10
Nervous System & Special Senses
Musculoskeletal Sys/Skin & Subcutaneous Tissue
Cardiovascular System 8-12
Respiratory System 7-11
Gastrointestinal System 7-11
Renal & Urinary System & Male Reproductive
Pregnancy, Childbirth & the Puerperium 4-8
Female Reproductive System & Breast 4-8
Endocrine System 4-8
Multisystem Processes & Disorders 5-9
Biostatistics & Epidemiology/Population Health / Interpretation of Medical Literature 1-5

* Percentages are subject to change at any time. See the USMLE Web site for the most up-to-date information.

Physician Tasks/Competencies

An additional organizing construct for Step 2 CK design is physician tasks and competencies. Each test item is constructed to focus on assessing one of the competencies listed in Table 2. Click here for detailed information about the physician tasks and competencies outline

Table 2: Step 2 CK Physician Task/Competency Specifications

Competency Range, %
Medical Knowledge: Applying Foundational Science Concepts 12-16
Patient Care: Diagnosis

  • History/Physical Examination
  • Laboratory/Diagnostic Studies
  • Diagnosis
  • Prognosis/Outcome
Patient Care: Management

  • Pharmacotherapy
  • Clinical Interventions
  • Mixed Management
Systems-based Practice & Patient Safety
Practice-based Learning & Improvement

Percentages are subject to change at any time. See the USMLE website for the most up-to-date information.

Each Step 2 CK examination covers content related to the traditionally defined disciplines listed in Table 3.

Physician Tasks/Competencies

An additional organizing construct for Step 1 design is physician tasks and competencies. Each test item is constructed to assess one of the competencies listed in Table 3.

Table 3: Step 1 Physician Tasks/Competencies Specifications*

Competency Range, %
Medicine 50-60


Pediatrics 20-25
Obstetrics & Gynecology
Psychiatry 10-15

* Percentages are subject to change at any time. See the USMLE website for the most up-to-date information.

Step 2 CK consists of multiple-choice questions (MCQs) prepared by examination committees composed of prominent faculty members, teachers, investigators, and clinicians who make up the USMLE Test Material Development Committees. All committee members have recognized expertise in their respective fields. They are selected to provide broad representation from the academic, practice, and licensing communities across the United States and Canada.

Test questions focus on the principles of clinical science that are deemed important for the practice of medicine under supervision in postgraduate training.

The content description is not intended as a curriculum development or study guide, but rather models the range of challenges that will be met in the actual practice of medicine. 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.

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


  • 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-Item Questions

This is the traditional, most frequently used multiple-choice format. It consists of a vignette and question followed by three to twenty-six options that are in alphabetical or logical order. The response options in this format are lettered (eg, A, B, C, D, E). You are required to select the one best answer to the question. Other options may be partially correct, but there is only ONE BEST answer.

Example Item

A 32-year-old woman with type 1 diabetes mellitus has had progressive renal failure over the past 2 years. She is not yet on 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?

  1. Acute blood loss
  2. Chronic lymphocytic leukemia
  3. Erythrocyte enzyme deficiency
  4. Erythropoietin deficiency
  5. Immunohemolysis
  6. Microangiopathic hemolysis
  7. Polycythemia vera
  8. Sickle cell disease
  9. Sideroblastic anemia
  10. β-Thalassemia trait

(Answer: D)

Sequential Item Sets

A single patient-centered vignette may be associated with two or three consecutive questions about the information presented. Each question is associated with the initial patient vignette but is testing a different point. You are required to select the ONE BEST answer to each question. Questions are designed to be answered in sequential order. You must click “Proceed to Next Item” to view the next item in the set; once you click on this button, the next question will be displayed, and you will not be able to change the answer to the previous question.

Abstract Format
The abstract item format includes a summary of an experiment or clinical investigation presented in a manner commonly encountered by a physician, eg, as an abstract that accompanies a research report in a medical journal. Examinees must interpret the abstract in order to answer questions on various topics, including

  • Decisions about care of an individual patient
  • Biostatistics/epidemiology
  • Pharmacology/therapeutics
  • Use of diagnostic studies