Everything You Need To Know About the Structure of Step 2 CK – 2020 Update

  • /Reviewed by: Amy Rontal, MD
  • An update of our October 2016 article covering the USMLE Step 2 CK exam’s content and structure.

    After you conquer Step 1, it’s time to think about how you will tackle Step 2. The second exam in the USMLE series tests medical students on their knowledge of the clinical sciences and their patient care skills, which is why it is called the USMLE Step 2 CK (Clinical Knowledge). Step 2 emphasizes prevention and health promotion. Medical students typically take Step 2 at the end of their third year after they have had some exposure to clinical experiences.

    (Note: There is also a Step 2 CS in the Step 2 series of tests, but the USMLE program announced in May 2020 they are suspending that test for the next 12-18 months.)

    Below we explain the structure of the Step 2 CK exam and list some updated information since we last covered this topic in 2016, that will be helpful as you prepare a study plan.


    The USMLE Step 2 CK is divided into 8 blocks of multiple-choice questions. The number of questions may vary between blocks. The test will inform you how many questions are in a given block before you begin. You have the option to take a 15-minute tutorial prior to taking the exam. If you finish early on one or more blocks, your cumulative break time between blocks may exceed 45 minutes. Below is a breakdown of the time and number of questions allotted on Step 2.

    • Total Testing Time: 9 hours
    • Time per Block: 60 minutes
    • Break Time Allotted: 45 minutes
    • Total Multiple Choice Questions: No more than 318
    • Questions per Block: No more than 40

    There are 3 types of multiple-choice questions on Step 2: Single-Item Questions, Sequential-Item Sets, and Abstract Set Questions.

    1. Single-Item Questions will have 3 to 26 answer choices. You must choose the most correct answer. Only one answer is best, while others may only be partially correct.
    2. Sequential-Item Sets contain 2 or 3 consecutive questions that each address the same patient scenario. When you answer one of these questions, you will be unable to return to an earlier question to change your answer choice.
    3. Abstract Set Questions refer to clinical summaries and build off of what would be included as an abstract in medical journals. These questions require an integrated understanding of the abstract materials covering a range of clinical topics.

    For examples of the above question types, see the USMLE Step 2 CK’s Sample Questions.


    Below you will find distribution ranges that tell you the amount of questions you can expect for each topic. In addition to testing content knowledge of systems, the USMLE Step 2 CK also tests physician tasks and competencies. The distribution of questions that test physician tasks and competencies are also listed below.

    Topic Distribution

    General Principles: 1-3%

    Organ Systems
    Cardiovascular System: 8-12%
    Respiratory System: 7-11%
    Gastrointestinal System: 7-11%
    Behavioral Health: 6-10%
    Nervous System and Special Senses: 6-10%
    Musculoskeletal System/ Skin and Subcutaneous Tissue: 6-10%
    Multisystem Processes and Disorders: 5-9%
    Blood and Lymphoreticular System: 4-7%
    Immune System: 4-6%

    Other Subjects
    Biostatistics, Epidemiology, Population Health, and Interpretation of Medical Literature: 1-5%
    Social Sciences: 3-7%

    • Legal and Ethical Issues
    • Professionalism
    • Systems-Based Practice
    • Patient Safety

    Physician Tasks and Competencies
    Patient Care: 62-77%

    • Laboratory and Diagnostic Studies
    • Diagnosis
    • Prognosis and Outcomes
    • Health Maintenance and Disease Prevention
    • Pharmacotherapy
    • Clinical Interventions
    • Mixed Management

    Medical Knowledge: Applying Foundational Science Concepts: 12-16%
    Other Topics: 3-7%

    • Practice-Based Learning and Improvement
    • Professionalism
    • System-Based Practice
    • Patient Safety
    • Communication

    Preparing for the USMLE Step 2 CK

    To see the most popular USMLE Step 2 CK textbooks, lecture series, question banks, and flashcards that our customers use, visit cramfighter.com/stats.

    Below are some frequently asked questions regarding Step 2 CK exam preparation.

    1. How long do most students study for Step 2 CK? According to our statistics, our medical student customers study for Step 2 for an average of 78 days.
    2. When are the most popular months to take Step 2 CK? The top three months among Cram Fighter users for taking Step 2 CK are July, June, and August. For a complete list of when our customers most often take Step 2 CK, visit our page with the most popular months.
    3. What do I need to score on Step 2? The minimum passing score for the USMLE Step 2 CK is a 209. In the United States and Canada, 96% of medical students passed Step 2 in the 2017-2018 academic year. The mean score for the 2018-2019 academic year was 243, with a standard deviation of 16.

    Wrapping up, we’d like to add that since USMLE Step 1 will be moving from a 3-digit scored exam to a pass or fail result in 2022, scoring well on Step 2 CK may be more relevant than ever before. Because of the change to Step 1 scoring’s importance for admission to residency programs, this could lead to Step 2 CK’s value increasing. As such, achieving a high Step 2 CK score could become more essential for matching into the residency program you want. Only time will tell how the coming changes to the USMLE Step 1 affect the importance of the Step 2 CK exam.

    To set up your study schedule for Step 2 CK using Cram Fighter, sign up for our 7-day free trial today.

    About the Author

    Erica Forrette is the former Director of Marketing at Cram Fighter.