Step 3 CCS Cases: Complete Walkthrough
How the Step 3 Computer-based Case Simulations (CCS) work, the scoring rubric, the time-management strategy, and the 10 case archetypes you'll encounter.
Step 3 Computer-based Case Simulations (CCS) feel completely different from any other exam component you've taken. Unlimited freedom to order tests, advance time, and make management decisions — but every action is scored. Here's how to navigate them.
What CCS actually is
CCS is the second day of Step 3. You manage 13 simulated patient cases over ~4 hours. Each case runs for a fixed amount of in-simulation time (10 or 20 minutes real time, days to weeks in simulated time). You order tests, write prescriptions, move the patient between care settings, and advance the clock — all in a stripped-down interface that mimics an EHR.
The scoring rubric (what we know)
- Diagnostic completeness: did you order the necessary workup?
- Therapeutic appropriateness: did you start correct treatment?
- Sequencing: did you act in the right order?
- Avoidance of harm: did you avoid contraindicated actions?
- Setting transitions: did you move the patient to the right level of care?
USMLE doesn't publish the exact rubric. Above is the consensus from prep providers and student debriefs. The exam rewards correct actions and penalizes harmful ones; benign-but-unnecessary actions are largely neutral.
Time management
Each case has a hard clock. Don't burn real-time minutes deliberating — order what you need, advance the clock, react to changes. Cases that run their full 10 or 20 minutes without you finishing the workup will score lower than cases where you reach a final disposition with time to spare.
The 10 case archetypes
- Acute chest pain (MI rule-out workup, anticoag, transfer to cath lab)
- Acute abdomen (surgical consult, imaging, NPO, IV fluids)
- Septic shock (cultures, fluids, broad-spectrum, vasopressors, ICU)
- DKA (insulin drip, potassium, fluids, monitoring)
- Stroke (CT, tPA window, neurology consult)
- GI bleed (IV access, PRBCs, EGD)
- Pediatric fever (workup by age, empiric antibiotics if indicated)
- Pre-eclampsia (BP control, magnesium, delivery planning)
- Acute psychiatric emergency (safety, hold criteria, restraints rules)
- Outpatient chronic disease management (vaccinations, screenings)
Common scoring leaks
- Forgetting baseline vitals and basic labs at presentation
- Failing to update orders when the patient transitions settings (ED → floor → ICU)
- Ordering studies but never checking the results
- Discharging without follow-up scheduling, vaccinations, or counseling
- Skipping the time-advance steps to see if treatment is working
Recommended prep
UWorld's CCS module is the standard. Run through all 50+ practice cases, then practice the official USMLE CCS tutorial software (free download) until the interface is muscle memory. The interface itself is the largest barrier — content knowledge transfers from Step 2 CK with minimal additional study.
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