Your USMLE® Step 2 CK Questions Answered: The Osmosis Ultimate Guide

Osmosis Team
Published on Jun 11, 2020. Updated on Jun 20, 2024.

The medical education journey often seems like it completely revolves around board exams! Though they can be intimidating and challenging, they’re also important milestones on your path to becoming a doctor. USMLE® Step 2 CK (full name USMLE Step 2 Clinical Knowledge) is one such medical licensing examination. Luckily, you’re in the right place to learn everything there is to know about it! 

Ready to learn how to crush this exam? Let’s dive in!

Osmosis illustration of medical students dreaming of acing USMLE® Step 2 CK.

What is USMLE Step 2 CK?

USMLE Step 2 is the board exam that follows USMLE Step 1. It originally consisted of two parts: USMLE Step 2 CS (Clinical Skills) and USMLE Step 2 CK (Clinical Knowledge). USMLE Step 2 CS tested clinical skills (taking a history, performing a physical examination, determining a diagnosis) using a series of live patient encounters, while USMLE Step 2 CK evaluates clinical knowledge through a computer-based multiple-choice exam. On January 26, 2021, the USMLE formally announced that USMLE Step 2 CS would be discontinued.

According to USMLE, “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.” Most questions describe clinical scenarios, and examinees are asked to determine the diagnosis, prognosis, mechanism of disease, or next steps.

When do I take USMLE Step 2 CK?

MD students in the United States take USMLE Step 2 CK in the fourth year of their medical education journey, following the completion of their clinical rotations and shelf exams. Some may choose to complete the exam soon after rotations while their clinical knowledge is fresh, while others might delay to maximize study time and focus on residency interviews. Medical students must pass USMLE Step 2 CK in order to graduate. 

International medical students hoping to match in the United States must pass  USMLE Step 2 to qualify for ECFMG (Educational Commission for Foreign Medical Graduates) certification. ECFMG assesses whether international medical graduates are prepared to enter residency or fellowship programs in the US. To participate in the Match, IMGs must be eligible for ECFMG certification, so they may structure their board exam schedule around achieving certification in time to apply to residency.

USMLE Step 2 CK exam topics and their division

USMLE Step 2 CK tests a broad range of topics. Not all topics will necessarily be tested, but it’s important to cover your bases and make sure you’re adequately prepared to address any topic on USMLE’s content outline.

You can expect to be assessed on normal/abnormal processes of individual organ systems (including principles of therapy), biostatistics, and social sciences. See the comprehensive list in Table 1.

Table 1: Step 2 Test Specifications*

Osmosis illustration of USMLE® Step 2 CK test specifications.

As Step 2 CK is centered on clinical knowledge, physician tasks and competencies will also be tested!

Table 2: Step 2 CK Physician Task/Competency Specifications*

Osmosis illustration of USMLE® Step 2 CK physician/task competency specifications.

Though the knowledge you’ve accumulated from your clinical rotations will certainly come in handy for every section of Step 2 CK, it’ll be particularly useful for answering questions related to the six traditionally defined disciplines in Table 3.

Table 3: Step 2 CK Discipline Specifications*

Osmosis illustration of USMLE® Step 2 CK discipline specifications.

In addition to the above, USMLE has announced that beginning no earlier than September, Step 2 CK will include more questions about professionalism, patient safety, systems-based practice, and legal/ethical issues. Make sure to prepare accordingly once the changes take effect!

* Note that percentages are subject to change at any time.

Osmosis illustration of professionalism.

What types of questions appear on USMLE Step 2 CK?

During the USMLE Step 2 Clinical Knowledge exam, you will encounter three different types of questions:

1. Single-item questions

Single-item questions will ask you to choose the best answer from between three to 26 options. Some of the answers are partially correct, but don't let these throw you off: only choose the answer you are certain is 100% correct.

2. Sequential-item sets

Sequential item sets use ordered questions attached to a single clinical vignette. Answering one question in the sequence will bring you to the next one; once you've moved forward in the set, there's no way to go back to change your previous answers.

3. Abstract-based questions

With this type of question, you will be provided with an abstract of an experiment or clinical investigation and asked to answer questions about it. With these questions, you want to be careful to balance your time between scrutinizing the abstract and determining your answer. These questions are designed to test your ability to synthesize information presented in an abstract to make clinical decisions.

What are the best USMLE Step 2 CK study resources?

Tackling Step 2 CK will be intimidating at first. The key to success is to get organized and create a comprehensive plan. First, take stock of resources you should invest in. The following materials will put you on the road to success:

Online Resources

  • Osmosis: Check out our Clinical Reasoning library, Microbiology, Biostatistics and Epidemiology videos, and our Pharmacology series to prepare for Step 2. We also have an enormous Step 2 Question Bank, described in more detail below.

  • UWorld: UWorld is a non-negotiable resource. If you’ve taken and passed Step 1, you’re likely already familiar with it. Take advantage of its extensive question bank and self-assessments.

The following are some of the most common textbook options. While you don’t necessarily have to use a physical book given all the fantastic online resources listed above, you may want a text to refer to. Remember not to spread yourself thin across resources—stick to one book!

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Osmosis illustration of a medical student struggling to deal with multiple texts while studying for USMLE® Step 2 CK.

How do I register for USMLE Step 2 CK?

You’ve taken and passed Step 1, and you’re ready to move onto Step 2. Congratulations! It’s time to register. You will be assigned an eligibility period during which you can schedule your exam. Note that if you decide to reschedule, your new test date must fall within your assigned eligibility period.

If you’re a medical student or graduate in the United States or Canada, you must apply to take Step 2 CK through the NBME and pay a registration fee. You may be subject to fees in order to reschedule your test date depending on proximity to the date.

However, if you’re a medical student or graduate outside the United States or Canada, you must apply to take Step 2 CK through the ECFMG and pay a registration fee. Rescheduling fees depend on your testing region.

Osmosis illustration of the musculoskeletal system.

How do I prepare before USMLE Step 2 CK?

Having Step 2 CK on the horizon can be daunting, but it need not be as long as you stick to a schedule and take good care of yourself.

Make your clerkships count

You will learn valuable clinical medicine from your clerkships. Pay attention, familiarize yourself with any new information you come across, listen closely, ask questions, and study hard for your shelf exams. Aim to excel! Many students take Step 2 CK soon after rotations, so quality learning on the ground definitely pays off. The stronger your foundation, the easier it will be to jump into studying for Step 2 CK!

Create a plan

It’s essential to create a study schedule. As you’ve studied for Step 1 and built robust study habits throughout medical school, you should have a good idea of what techniques work for you. First, select the resources you’re going to be using. Some are non-negotiable (like UWorld), but others (like textbooks) you can take or leave.

Next, map out the time you have until exam day. Be realistic about how many hours of effective studying you can put in each day, and make sure to account for break time and rest days. 

Finally, list out your weekly goals, and create a plan. Consider using the time-blocking technique. Treat your to-do list as the skeleton of your plan, and carve out specific hours to complete tasks. The more detailed your plan, the better! Research shows that single-tasking (the foundation of time-blocking) significantly boosts productivity. Also, take stock of your current habits: when during the day are you usually most productive? Plan to complete your most intensive tasks during that “block” of time. 

For example, spend your mornings watching Osmosis videos about topics you struggled with the day before. In the afternoon, work through a set of UWorld questions. In the evening, review your daily allotment of Anki cards. At the end of the week, take an assessment and gauge your weaknesses. Rinse and repeat!

Osmosis illustration of a student performing single-tasking successfully.

Cultivate a healthy lifestyle

Don’t make the mistake of sacrificing a healthy lifestyle to squeeze in more study time. Your health should remain a priority. While good health is valuable for more than just achieving a great Step 2 CK score, note that you’ll study more effectively (and retain more information) as a well-rested, well-fed student than as a lethargic, unhealthy one.

Osmosis illustration of healthy lifestyle while studying for Step 2 CK.

Here are some healthy lifestyle tips to put into practice:

  • Sleep and wake up at the same time every day, and aim for 7-8 hours of rest. Regularity makes for more restorative sleep.

  • Eat a healthy diet. Plan out meal times and take some time over weekends to prepare your food for the week. Having meals that are ready to go will help you avoid impulsive, unhealthy snacking.

  • Exercise daily. Exercise is great for your brain! Try this student’s no-equipment, at-home workout routine, or go for a brisk, 15-minute walk around the block.

  • Practice mindfulness. Meditative practices can boost self-esteem and alleviate anxiety. Try this 10-minute meditation once a day.

Osmosis illustration of a healthy brain.

Take breaks as needed

Break time can be just as important as study time. Time off allows you to recharge, which is why scheduling breaks is so important. A great schedule will enable you to focus on relaxing because you’ll know that every task has been incorporated into your plan. Don’t spend your break fretting over the work you have left to do: give yourself permission not to think about studying. This is also a good time to examine your journey with perspective: getting to take Step 2 CK means you’re firmly on the path to living out your dream of becoming a doctor!

How long does the USMLE Step 2 CK exam take?

Step 2 CK is a one-day examination that lasts roughly 9 hours. It’s divided into 8 60-minute blocks. There are at most 40 questions per block and 318 questions per exam; the actual number of questions may vary. 

You have, at minimum, 45 minutes of break time, and an optional 15-minute tutorial at the start of the exam. You can choose when to take your break time, but cannot interrupt a block for a break. It’s wise to plan out in advance when you’ll take breaks. For example, you can choose to take a 10 minute break after block 2 and block 4, and an extended break (20 minutes) after block 6 to gear up for the final sprint. Note that if you finish a block before the allotted time expires, you can use the extra time to extend your breaks.

What should I bring to the USMLE Step 2 CK exam?

Since Step 2 CK is computer-based, there’s no need to bring a number 2 pencil! Check out the following lists of things to bring.


  1. Valid, unexpired identification with your photo, name, and signature. You will NOT be allowed to take the exam without this.

  2. Your USMLE scheduling permit, usually sent in an email. Make sure the name on your scheduling permit exactly matches the one on your ID. Note that you can bring a physical or electronic copy, so a screenshot of it on your phone may suffice.

Osmosis illustration of a medical student bringing ID to USMLE Step 2 CK.

Strongly recommended

  1. Beverages. It’s important to stay hydrated during such a long exam. Avoid anything sugary or caffeinated - you don’t want to feel jittery or crash.

  2. Snacks. You’ll definitely get hungry at some point. Pack healthy snacks. Try: fruit, a sandwich, trail mix, or whole grains. Don’t overeat, lest you get lethargic!

Osmosis illustration of someone packing a lunch to bring to USMLE Step 2 CK.


  1. Foam earplugs. You can bring these into the testing center to reduce distracting noises.

  2. Personal item exceptions. Here is an official list of personal items that you can bring into the testing station WITHOUT making a request or submitting documentation.

Only foam earplugs and personal item exceptions (refer to the list) are permitted in the testing room. You can only access your other possessions during breaks outside of the testing room. You will be provided with a personal locker to store your belongings in.

Remember: when in doubt, it’s best to avoid bringing an item with you. If you feel the need to bring something into the testing room that isn’t explicitly listed as a personal item exception, submit a request to the USMLE in advance.

Osmosis illustration of the nervous system.

What's the USMLE Step 2 CK exam day like?

Though your priority before test day has of course been to master the material, it’s important to consider logistics as well to maximize your performance on Step 2 CK.

Test day

On test day, arrive at the testing center 30 minutes early with your snacks, valid photo identification, and scheduling permit. Expect to undergo security procedures. You will be:

  • Scanned with a device designed to detect prohibited items

  • Asked to empty your pockets

  • Asked to show your photo identification

  • Required to have your fingerprint captured using biometric technology (only available at some locations)

  • Required to write your unique Candidate Identification Number (CIN) on a laminated note board provided to you

Note that you will likely have to repeat this process every time you return to the testing room after a break. On breaks outside of the testing station, you can access your phone and snacks.

When you sit down at your computer in the testing station for the first time, make sure to test your headphones. You can choose to complete an optional 15-minute tutorial, after which you will begin the first block. Stay calm, and don’t forget to take a deep breath!

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How long do I have to wait for my USMLE Step 2 CK exam results?

Congratulations on taking Step 2 CK! Results are usually available in 3–4 weeks, but delays do occur. The USMLE says to allow at least eight weeks for notification that your score is available. You can find announcements about any potential delays here.

What USMLE Step 2 CK score do I need to match?

Of course, Step 2 CK is a major part of your application to residency. A passing score is 209, but the data shows that you need a score well above a 209 to match to your preferred specialty. What score should you aim for? 

According to the NRMP’s 2020 report, Charting Outcomes in the Match, U.S allopathic seniors who matched to their preferred specialty had a mean Step 2 CK score of 247. U.S osteopathic seniors who matched, on the other hand, had a mean Step 2 CK score of 240. Finally, matched non-U.S. IMGs had a mean Step 2 CK score of 240

Of course, depending on the specialty you choose, you may need to aim higher. Find your preferred specialty in the table below.

Mean USMLE Step 2 Scores Of Students Who Matched Across Specialties

Osmosis table showing the mean USMLE® Step 2 CK scores across specialties.

* n/a = data not shown due to small sample size.

How will USMLE Step 1 becoming pass/fail impact the importance of USMLE Step 2 CK?

Early in 2020, the USMLE announced that it would change score reporting for Step 1 from a three-digit numeric score to a pass/fail outcome beginning no earlier than January 1, 2022. Though this decision had long been rumored, the announcement sent shock waves throughout the pre-medical and medical community. Of course, the foremost question on everyone’s mind was: how will this impact residency and fellowship applications? Will other components of applications be weighted differently, given Step 1’s historical importance?

Though this change has yet to be implemented, some outcomes seem likely. According to the NRMP, the vast majority of residency programs cite Step 1 as one of the most important factors in ranking applicants. Applicants could be differentiated on the basis of this standardized metric. Once Step 1 becomes pass/fail, it’s likely that greater importance will be placed on Step 2 CK performance.

Some hypothesize that school rank will matter more in the absence of Step 1 scores, but NRMP data indicate that less than half of residency programs cited “graduate of highly regarded U.S. medical school” as a factor in ranking applicants. It’s best to focus on what you can control: your board scores. That’s why you’re here!

What happens if I fail USMLE Step 2 CK?

Despite your intensive preparation for Step 2 CK, you’ve failed. First, take a deep breath: this isn’t the end of your journey, and it’s going to be okay. Take time to examine and accept your feelings, and then look ahead to the future. 

As mentioned earlier, Step 2 CK is required for graduation from medical school for US seniors, and ECFMG certification for IMGs. Here’s what you should do next:

Reach out to your academic advisor

Your school likely has resources in place for students who fail board exams. Reach out to your academic advisor immediately and discuss a plan for retaking Step 2 CK. This might necessitate rescheduling a rotation to make time for additional studying. IMGs may have to postpone participating in the Match, as Step 2 CK is a prerequisite for ECFMG certification.

Assess your mistakes

Don’t dive back into studying without reflecting deeply on why you failed. Did you cram? Was your understanding of a particular organ system shallow? Were you feeling ill on test day? Take honest stock of what went wrong. Don’t beat yourself up! Approach this exercise with an optimistic attitude: diagnosing the problem will help you succeed on your next attempt.

Seek support

In such a challenging moment, it’s important to lean on your social network for support. Ask to talk to a close friend or family member. Express your feelings honestly and reach out when you need to hear words of encouragement.

Refine your study plan

Gather your resources and create a new plan. Make sure that you’re directly tackling the problems that you experienced on your first attempt.

Reassess your specialty choice

Painful though it may be, it’s important to be honest with yourself. Many residency programs seldom or never consider applicants who fail Step 2 CK on the first attempt. If you were hoping to apply to a competitive specialty, you may have to change your plan based on the likelihood of matching into that particular specialty.

Strengthen other aspects of your application

Though board scores are important, they aren’t the only important components of a residency application. Among other things, program directors also consider:

  • Letters of recommendation in the specialty

  • Personal statement

  • Clerkship grades

  • Class ranking

  • Professionalism, ethics, and leadership qualities

Despite this setback, your application can still shine. Make sure to ask your recommenders for strong letters. Refine your personal statement until it clearly expresses why you’re a great fit for the program. Highlight other academic achievements.

You can do it!

Osmosis illustration of the cardiovascular system.

How has COVID-19 impacted USMLE Step 2 CK?

As COVID-19 unraveled in early 2020, plans for the year had to evolve accordingly. On April 10, 2020, Prometric, the U.S-based test administration company, announced that test centers would be closed until May 1, 2020; following that, closures were extended to May 31, 2020. However, USMLE is considered an essential program, so a limited number of test centers have resumed testing since May 1, 2020. Of course, any examinees who expected to take Step 2 CK throughout this period were forced to reschedule their test dates. Rescheduling fees have been waived for all USMLE Step examinations until further notice.

When examinees apply to take Step 2 CK, they are assigned a three-month eligibility period during which they can schedule (and reschedule) their exam. In response to test center closures and exam cancellations, USMLE has extended eligibility periods to December 2020 for those with an unexpired eligibility period with an end date in 2020. This change was automatic and valid regardless of which country in which examinees are testing.

Currently, enhanced safety measures are being implemented in Prometric test centers. Examinees will be seated in accordance with social distancing guidelines and must bring a mask to the test center. USMLE has also announced a three-phase plan to expand testing capacity for Step 1, Step 2 CK, and Step 3, the third phase of which will deliver USMLE through remote proctoring.

Many examinees are understandably frustrated about this turn of events, as COVID-19 has disrupted careful planning. Examinees should be vocal about their concerns and issues as they arise. Remember to practice self-care: here are some tips for overcoming anxiety during the pandemic.

You can check the USMLE Announcements page for any new updates regarding Step 2 CK.

How can Osmosis help me study for USMLE Step 2 CK?

Resource selection is one of the most important parts of preparing for Step 2 CK. Luckily, you’re in the right place! Osmosis is well-equipped to help you prepare effectively for Step 2 CK.

Check out our Clinical Reasoning library, which will help you acquire the clinical reasoning skills necessary to treat various conditions. Apply this knowledge throughout your rotations. Remember: making the most of your learning experience on the wards is one important way to conquer Step 2 CK.

Also see the Clinician’s Corner, where you’ll learn essential professional skills directly from the source: current and future clinicians!

Of course, no study schedule is complete without practice. Osmosis has over 3,500 case questions for Step 2 CK, complete with detailed answer explanations. Apply your knowledge here.

Best of luck preparing for Step 2 CK. We’re rooting for you!

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The United States Medical Licensing Examination (USMLE®) is a joint program of the Federation of State Medical Boards (FSMB®) and National Board of Medical Examiners (NBME®). Osmosis is not affiliated with NBME nor FSMB.

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