USMLE (NBME & FSMB)
USMLE Step 2 CK
United States Medical Licensing Examination, Step 2 Clinical Knowledge
The clinical-knowledge exam in the US physician licensing sequence, testing the application of medical knowledge and patient-centered skills under supervised practice. Its three-digit score is a major factor in residency selection.
Full program: 14 decks, 881 cards.
What's on the exam
USMLE Step 2 CK Content Outline & Specifications (system ranges per USMLE; decks group some systems, so weights are approximate)
General Principles of Foundational Science
~2% (outline now places this under Human Development, 2–4%)Applied biochemistry · Pharmacology principles · Microbiology in clinical context · Pathophysiology fundamentals
Immune System, Blood & Lymphoreticular
5–10%Anemias & transfusion · Coagulopathies · Hematologic malignancies · Immunodeficiency & autoimmunity · Allergic & hypersensitivity disorders
Behavioral Health & Mental Disorders
5–10%Mood & anxiety disorders · Psychotic disorders · Substance use disorders · Psychopharmacology · Childhood & developmental psychiatry
Nervous System & Special Senses
5–10%Stroke & cerebrovascular disease · Seizure disorders · Neurodegenerative & demyelinating disease · Headache & pain · Ophthalmologic & ENT disorders
Musculoskeletal, Skin & Subcutaneous Tissue
6–12%Arthritis & connective tissue disease · Fractures & orthopedic injury · Dermatologic disorders · Skin & soft-tissue infections · Bone & soft-tissue tumors
Cardiovascular System
6–12%Acute coronary syndromes · Heart failure & arrhythmias · Hypertension management · Valvular & congenital disease · Vascular disorders
Respiratory System
5–10%Pneumonia & respiratory infections · Asthma & COPD · Pulmonary embolism · Lung cancer · Critical care & ventilation
Gastrointestinal System
5–10%GI bleeding · Inflammatory bowel disease · Hepatobiliary & pancreatic disease · GI malignancies · Acute abdomen & surgical evaluation
Renal, Urinary & Male Reproductive
~7% (part of Renal/Urinary & Reproductive, 7–13%)Acute & chronic kidney disease · Electrolyte & acid-base disorders · Urinary tract infections & stones · Prostate disease · Genitourinary malignancies
Pregnancy, Female Reproductive & Breast
~9% (Pregnancy/Childbirth 3–7% plus share of Reproductive)Antepartum & prenatal care · Labor & delivery complications · Gynecologic disorders · Contraception & menopause · Breast disease & malignancy
Endocrine & Metabolic
3–7%Diabetes management · Thyroid disorders · Adrenal & pituitary disease · Calcium & bone metabolism · Lipid & nutritional disorders
Multisystem Processes, Biostatistics & Population Health
~17% (Multisystem 4–8%, Biostatistics/Population Health 3–5%, Social Sciences/Ethics/Patient Safety 10–15%)Infectious & sepsis syndromes · Fluid, electrolyte & multisystem disorders · Biostatistics & epidemiology · Patient safety & quality improvement · Preventive care & screening · Geriatrics & end-of-life care
Frequently asked questions
How much does the USMLE Step 2 CK cost?
The USMLE Step 2 CK costs $695. Approximately $695 registration fee for US/Canadian students; international test-delivery surcharges may apply.
How long is the USMLE Step 2 CK and how many questions does it have?
Up to 318 items across 16 blocks — Up to 9 hours in one day.
What do you need to pass the USMLE Step 2 CK?
Three-digit score reported; passing standard is 218 (effective July 1, 2025).
Can you retake the USMLE Step 2 CK?
Up to four attempts per Step; no more than three attempts within a 12-month period.
What is the best way to study for the USMLE Step 2 CK?
Start from the official outline and your primary study materials: the exam is weighted by domain (General Principles of Foundational Science ~2% (outline now places this under Human Development, 2–4%), Immune System, Blood & Lymphoreticular 5–10%, Behavioral Health & Mental Disorders 5–10%, Nervous System & Special Senses 5–10%, Musculoskeletal, Skin & Subcutaneous Tissue 6–12%, Cardiovascular System 6–12%, Respiratory System 5–10%, Gastrointestinal System 5–10%, Renal, Urinary & Male Reproductive ~7% (part of Renal/Urinary & Reproductive, 7–13%), Pregnancy, Female Reproductive & Breast ~9% (Pregnancy/Childbirth 3–7% plus share of Reproductive), Endocrine & Metabolic 3–7%, Multisystem Processes, Biostatistics & Population Health ~17% (Multisystem 4–8%, Biostatistics/Population Health 3–5%, Social Sciences/Ethics/Patient Safety 10–15%)). Once you've learned the material, spaced-repetition flashcards organized by those domains are an efficient way to retain it and refresh it before test day.
Ready to prepare?
Our USMLE Step 2 CK program is organized by this outline's domains and scheduled by spaced repetition, with a path from first card to test day.
Flashcards are a memory tool. Learn the material first, then use NoReread to retain it and refresh what you already know. It doesn't replace studying the subject.