Step 2 CK at-a-glance (2025)
Before you build a study plan, you must understand the exam you are training for. The USMLE Step 2 CK is a one-day examination, totalling approximately nine hours. Here are the facts:
- Duration: One day, divided into eight 60-minute blocks.
- Questions: There are no more than 40 questions per block, with a maximum of 318 items for the entire exam.
- Breaks: You have a minimum of 45 minutes of break time, plus an optional 15-minute tutorial. We recommend skipping the tutorial (after you've familiarised yourself with the interface via practice tests) and adding this time to your break.
- Item formats: Most items are single-best-answer multiple-choice questions. You will also encounter sequential question sets, abstracts, and items featuring audio or video findings (e.g., a heart murmur or physical exam finding).
This structure means you have, on average, 90 seconds per item. Pacing, endurance, and efficient retrieval of knowledge are paramount.
Prepare to the real blueprint, not guesses iatroX weights your practice to Step 2 CK systems, tasks, and disciplines, spaces your reviews automatically, and uses AI to challenge your reasoning—without compromising compliance. Start adaptive Step 2 CK practice at iatrox.com/us
The official blueprint you must map to
Your revision must be proportional to the exam's content. Do not waste time on low-yield topics. The USMLE provides a detailed content outline, which we have broken down here.
System specifications (Table 1)
This is what you need to know. Note that normal processes are usually assessed within the context of a disease.
| System | Percentage Range |
|---|---|
| Human Development | 2%–4% |
| Immune System | 3%–5% |
| Blood & Lymphoreticular System | 4%–6% |
| Behavioural Health | 5%–10% |
| Nervous System & Special Senses | 5%–10% |
| Musculoskeletal System/Skin & Subcutaneous Tissue | 6%–12% |
| Cardiovascular System | 6%–12% |
| Respiratory System | 6%–12% |
| Gastrointestinal System | 6%–12% |
| Renal/Urinary & Reproductive Systems (Male/Female) | 7%–13% |
| Pregnancy, Childbirth & Puerperium | 4%–6% |
| Female Reproductive & Breast | 4%–6% |
| Endocrine System | 4%–6% |
| Multisystem Processes & Disorders | 4%–6% |
| Biostatistics & Epidemiology/Population Health, etc. | 3%–5% |
| Social Sciences, Legal, Ethical & Systems Issues | 10%–15% |
| (Source: USMLE Step 2 CK Content Outline) |
Physician tasks & competencies (Table 2)
This is how your knowledge will be tested. Note the heavy focus on diagnosis and management.
| Physician Task / Competency | Percentage Range |
|---|---|
| Patient Care: Diagnosis | 16%–20% |
| Patient Care: Labs/Diagnostics | 13%–17% |
| Patient Care: Mixed Management | 12%–16% |
| Patient Care: Pharmacotherapy | 8%–12% |
| Patient Care: Clinical Interventions | 3%–5% |
| Patient Care: Health Maintenance/Prevention | 7%–11% |
| Patient Care: Prognosis/Outcome | 4%–6% |
| Systems-based Practice & Patient Safety | 5%–7% |
| (Source: USMLE Step 2 CK Competency Specifications) |
Disciplines (Table 3)
This table shows the discipline-based allocation of questions. The clear takeaway is that this is a medicine-heavy exam.
| Discipline | Percentage Range |
|---|---|
| Medicine | 55%–65% |
| Surgery | 20%–30% |
| Paediatrics | 17%–27% |
| Obstetrics & Gynaecology | 10%–20% |
| Psychiatry | 10%–15% |
| (Source: USMLE Step 2 CK Discipline Specifications) |
Converting the blueprint into a study design
The evidence-led method
The most effective study plans are built on proven learning science:
- Retrieval practice: Testing yourself (e.g., doing MCQs) is a far more powerful learning event than passively rereading or watching videos.
- Spaced repetition: Reviewing information at increasing intervals over time is the most effective way to build durable, long-term memory.
- Interleaving: Mixing topics and systems in a single block (rather than studying one system for a whole day) is harder but builds the mental flexibility needed for the exam.
Where AI adds value—ethically
AI tools can be powerful study partners if used correctly. Use them to:
- Reframe explanations: Ask an AI to "explain this concept in a different way" or "explain the mechanism of action."
- Build differential scaffolds: Use AI to brainstorm differential diagnoses for a given presentation.
- Practice "teach-back": Explain a concept to an AI and ask it to critique your explanation.
Crucially, never ingest or upload real exam items from a Q-bank. This is a breach of copyright and exam policy. Always use AI for your own learning and summarisation, and always verify its outputs against a trusted source.
Blueprint → weekly quotas
Your study plan must reflect the blueprint. This means dedicating 10–15% of your time to the "Social/Legal/Professionalism" domain and ensuring that roughly 40–50% of your practice questions are focused on the key tasks of "Diagnosis," "Labs/Diagnostics," and "Mixed Management."
A 6-week “sprint” plan (aggressive)
This plan is designed for candidates with a strong clinical rotation foundation, aiming for 25–30 hours of study per week.
- Weekly structure: 5 study days + 1 mixed review day + 1 rest day.
- Daily blocks: 2–3 timed MCQ sets (33–40 questions each) + 60–90 minutes of targeted review + 20–30 minutes of spaced repetition (e.g., Anki or the iatroX Quiz adaptive engine).
| Week | System & Task Focus |
|---|---|
| Week 1 | Systems: Cardiovascular & Respiratory.<br>Tasks: Diagnosis & Pharmacotherapy. |
| Week 2 | Systems: GI & Renal/Urinary/Reproductive.<br>Tasks: Labs/Diagnostics & Mixed Management. |
| Week 3 | Systems: Neuro & Behavioural Health.<br>Tasks: Diagnosis & Clinical Interventions. |
| Week 4 | Systems: MSK/Skin & Endocrine.<br>Tasks: Pharmacotherapy & Health Maintenance/Prevention. |
| Week 5 | Systems: Paediatrics & OB-GYN (inc. Pregnancy/Puerperium).<br>Tasks: Mixed Management & Prognosis/Outcome. |
| Week 6 | Systems: Multisystem, Sepsis, Oncology, Peri-op + Social/Legal/Professionalism.<br>Action: Full-length mock exam + deep error analysis. |
Quant target: ~1,000–1,200 MCQs. Every item you miss should be turned into a spaced card or fed into an iatroX micro-set for review at 2-day and 7-day intervals.
Build my 6-week plan in iatroX
A 12-week “standard” plan (realistic for most)
This plan is more sustainable, starting at 15–18 hours/week and ramping up to 20–25. It allows for more consolidation and spaced reviews.
| Weeks | System & Task Focus |
|---|---|
| Weeks 1–4: Foundations | One system per week (CVS/Resp, GI/Renal/Rep, Neuro/Behavioural, MSK/Skin/Endo).<br>Task focus: Diagnosis & Labs/Diagnostics. |
| Weeks 5–8: Application | Modules on OB-GYN, Paediatrics, and Pregnancy.<br>Task focus: Pharmacotherapy, Mixed Management, and Health Maintenance/Prevention. |
| Weeks 9–10: Integration | Multisystem disorders, Sepsis, Oncology, Peri-op.<br>Task focus: Systems-based Practice & Patient Safety.<br>Action: Sit one full-length simulation at the end of Week 10. |
| Weeks 11–12: Refinement | Personal weak-area loops. High-yield tables. Practice audio/video items.<br>Action: Two full-length mock exams with 48-hour spaced error reviews. |
Quant target: ~1,800–2,200 MCQs. Dedicate 20-30 minutes every day to your spaced recap. This is the single most important habit for building a high score.
Start adaptive Step 2 CK practice
Daily workflow (compliant, AI-assisted)
- Timed set: Do a 33–40 question timed block in your primary Q-bank (e.g., UWorld) or the iatroX US Q-bank.
- First-pass review: As you review your answers, classify your misses. Was it a knowledge gap, a reasoning error, a trap, or a time issue?
- AI “Socratic” assist: For a concept you truly don't understand, ask a de-identified, general question to an AI (e.g., "Explain the difference between a type 1 and type 2 RTA"). Do not copy/paste proprietary exam content.
- Spaced recap: Add your error topics to your iatroX adaptive quiz queue or your Anki deck. This is your most high-yield task of the day.
- Task alignment: Check your analytics. If you are weak on "Labs/Diagnostics," make sure your next few blocks are weighted towards that task.
Test-day strategy
- Use the 90-second-per-question heuristic. If you are stuck at 90 seconds, mark the item, make your best guess, and move on.
- Plan your breaks. A common strategy is to take a 5–10 minute break after every two blocks.
- Skip the 15-minute tutorial to add that time to your break bank.
- For audio/video items, play them once, read the stem, and play them again.
Frequently asked questions
- How many questions are on Step 2 CK?
- Up to 318 total items, delivered in eight 60-minute blocks (with a maximum of 40 questions per block) over a single nine-hour day.
- How is Step 2 CK content weighted?
- It is weighted by system (e.g., Cardiovascular 6–12%), physician tasks (e.g., Diagnosis 16–20%), and discipline (e.g., Medicine 55–65%). Your study plan must reflect these proportions.
- How should I adapt if I’m weak in Pharmacotherapy or Diagnostics?
- Your analytics will show this. For the next two weeks, ensure at least 1 in 3 of your practice questions are tagged with those competencies, in line with their high-yield USMLE ranges.
- Is AI allowed for preparation?
- Yes, you may use AI for studying, summarising concepts, and practising your reasoning. However, you must never copy or upload real exam content or breach exam security. Always follow all USMLE rules.