USMLE Step 2
Clinical Knowledge (CK)
Sample Test Questions
A Joint Program of the Federation of State Medical Boards of the United States, Inc., and the National Board of Medical Examiners®

This booklet updated July 2015.
Copyright © 2015 by the Federation of State Medical Boards of the United States, Inc. (FSMB), and the National Board of Medical Examiners® (NBME®). All rights reserved. Printed in the United States of America. The United States
Medical Licensing Examination (USMLE®) is a joint program of the FSMB and the NBME.

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CONTENTS

USMLE Step 2 CK Test Question Formats …………………………………...……….

3

Introduction to USMLE Step 2 CK Sample Test Questions …………………………..

5

Normal Laboratory Values ………………………………...………..…….….………..

6

USMLE Step 2 CK Sample Test Questions…………………………………………....

8

Answer Sheet for USMLE Step 2 CK Sample Test Questions………………………..

52

Answer Key for USMLE Step 2 CK Sample Test Questions……………………….…

53

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USMLE Step 2 CK Test Question Formats
Single-Item Questions
This is the traditional, most frequently used multiple-choice format. It consists of a vignette and question followed by three to twenty-six options that are in alphabetical or logical order. The response options in this format are lettered (eg, A,
B, C, D, E). You are required to select the one best answer to the question. Other options may be partially correct, but there is only ONE BEST answer.
Items with an associated abstract or pharmaceutical ad were introduced into the examination in August 2011. Each abstract or pharmaceutical ad appears as a 2- or 3-item set; there are no more than 5 of these item sets in each examination. Because item sets with an associated abstract or pharmaceutical ad may require more time to answer than traditional multiple-choice items, blocks that include these item sets contain fewer items.
Strategies for Answering Single One-Best-Answer Questions

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Read each question carefully. It is important to understand what is being asked.
Try to generate an answer and then look for it in the response option list.
Alternatively, read each response option carefully, eliminating those that are clearly incorrect.
Of the remaining response options, select the one that is most correct.
If unsure about an answer, it is better to guess since unanswered questions are automatically counted as wrong answers. Example Item: Single Question

A 32-year-old woman with type 1 diabetes mellitus has had progressive renal failure over the past 2 years. She has not yet started dialysis. Examination shows no abnormalities. Her hemoglobin concentration is 9 g/dL, hematocrit is 28%, and mean corpuscular volume is 94 μm3. A blood smear shows normochromic, normocytic cells. Which of the following is the most likely cause?
(A)
(B)
(C)
(D)
(E)
(F)

(G)
(H)
(I)
(J)

Acute blood loss
Chronic lymphocytic leukemia
Erythrocyte enzyme deficiency
Erythropoietin deficiency
Immunohemolysis
Microangiopathic hemolysis

(Answer: D)

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Polycythemia vera
Sickle cell disease
Sideroblastic anemia β-Thalassemia trait

Sequential Item Sets
A single patient-centered vignette may be associated with two or three consecutive questions about the information presented. Each question is associated with the initial patient vignette but is testing a different point. You are required to select the ONE BEST answer to each question. These questions are designed to be answered in sequential order. You must click “Proceed to Next Item” to view the next item in the set; once you click on this button, the next question will be displayed, and you will not be able to return to the previous question or change the answer to it.

Example Items: Sequential Questions
A 35-year-old woman is brought to the emergency department because of worsening pain and swelling of her right knee for the past 2 days. She has been taking acetaminophen for the knee pain during the past 2 days, but the pain is worse today. She has not had any trauma to the knee or any previous problems with her joints. She is otherwise healthy and she currently takes an oral contraceptive. She is sexually active and has a 10-year-old son who lives with her. She is a receptionist at a local hotel and she tells you she must stand often while working. She is 160 cm (5 ft 3 in) tall and weighs
52 kg (115 lb); BMI is 20 kg/m2. Temperature is 37.9°C (98.9°F). The right knee is erythematous, swollen, and tender; there is pain on movement. No other joints are affected. X-ray of the knee shows an effusion but no structural abnormalities of the joint.
Which of the following is the most appropriate next step in diagnosis?

(A)
(B)
(C)
(D)
(E)

Arthrocentesis of the knee
Blood cultures
Complete blood count
MRI of the knee
Urine cultures
(Answer: A)

Arthrocentesis is done. The synovial fluid is cloudy. Gram stain is negative. Analysis of the synovial fluid shows a leukocyte count of 120,000/mm3 and 90% neutrophils. Which of the following is the most appropriate additional test on the synovial fluid?

(A)
(B)
(C)
(D)
(E)

Culture for bacteria
Culture for fungus
Glucose measurement
Polarized light microscopy
Protein level
(Answer: A)

NOTE: When additional item formats are added to the examination, notice will be provided on the USMLE Web site
(http://www.usmle.org). You must monitor the Web site to stay informed about the types of items that occur in the examination, and you must practice with the downloadable sample test items available on the USMLE Web site in order to be fully prepared for the examination.

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Introduction to USMLE Step 2 CK Sample Test Questions
The following pages include 141 sample test questions. Most of these questions are the same as those you can install on your computer from the USMLE Web site. Please note that reviewing the sample questions as they appear on pages 8-51 is not a substitute for practicing with the test software. You should download and run the Step 2 CK examination tutorial and practice test items that are provided on the USMLE Web site well before your test date. The sample materials available on the USMLE Web site include additional items and item formats that do not appear in this booklet, such as abstract and pharmaceutical ad item sets, items with associated audio or video findings, and sequential item sets. You should become familiar with all item formats that will be used in the actual examination.
Although the sample questions exemplify content on the examination, they may not reflect the content coverage on individual examinations. In the actual examination, questions will be presented in random order. The questions will be presented one at a time in a format designed for easy on-screen reading, including the use of exhibit buttons for some pictorials and a Normal Laboratory Values button (Table included here on pages 6–7). Photographs, charts, and x-rays in this booklet are not of the same quality as the pictorials used in the actual examination. In addition, you will be able to adjust the brightness and contrast of the computer screen.
To take the following sample test questions as they would be timed in the actual examination, you should allow a maximum of one hour for each block, for a total of four hours. Please be aware that most examinees perceive the time pressure to be greater during an actual examination. An answer form for recording answers is provided on page 52. An answer key is provided on page 53. In the actual examination, answers will be selected on the screen; no answer form will be provided.

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LABORATORY VALUES
* Included in the Biochemical Profile (SMA-12)
REFERENCE RANGE
SI REFERENCE INTERVALS
BLOOD, PLASMA, SERUM
* Alanine aminotransferase (ALT), serum................. 8-20 U/L ....................................................8-20 U/L
Amylase, serum ...................................................... 25-125 U/L.................................................25-125 U/L
* Aspartate aminotransferase (AST), serum .............. 8-20 U/L.....................................................8-20 U/L
Bilirubin, serum (adult) Total // Direct ................... 0.1-1.0 mg/dL // 0.0-0.3 mg/dL ................2-17 μmol/L // 0-5 μmol/L
* Calcium, serum (Ca2+) ............................................ 8.4-10.2 mg/dL ..........................................2.1-2.8 mmol/L
* Cholesterol, serum .................................................. Rec: 7 μg/L
Immunoglobulins, serum
IgA ....................................................................... 76-390 mg/dL ............................................0.76-3.90 g/L
IgE ........................................................................ 0-380 IU/mL .............................................0-380 kIU/L
IgG ....................................................................... 650-1500 mg/dL ........................................6.5-15 g/L
IgM ...................................................................... 40-345 mg/dL ...........................................0.4-3.45 g/L
Iron ......................................................................... 50-170 μg/dL ............................................9-30 μmol/L
Lactate dehydrogenase, serum ................................ 45-90 U/L...................................................45-90 U/L
Luteinizing hormone, serum/plasma ...................... Male: 6-23 mIU/mL ..................................6-23 U/L
Female: follicular phase 5-30 mIU/mL .....5-30 U/L midcycle 75-150 mIU/mL .......................75-150 U/L postmenopause 30-200 mIU/mL ............30-200 U/L
Osmolality, serum ................................................... 275-295 mOsmol/kg H2O ..........................275-295 mOsmol/kg H2O
Parathyroid hormone, serum, N-terminal ............... 230-630 pg/mL .........................................230-630 ng/L
* Phosphatase (alkaline), serum (p-NPP at 30°C) ..... 20-70 U/L ..................................................20-70 U/L
* Phosphorus (inorganic), serum ............................... 3.0-4.5 mg/dL ...........................................1.0-1.5 mmol/L
Prolactin, serum (hPRL) ........................................ < 20 ng/mL ................................................< 20 μg/L
* Proteins, serum
Total (recumbent) ................................................. 6.0-7.8 g/dL ...............................................60-78 g/L
Albumin ................................................................ 3.5-5.5 g/dL................................................35-55 g/L
Globulin ............................................................... 2.3-3.5 g/dL................................................23-35 g/L
Thyroid-stimulating hormone, serum or plasma ..... 0.5-5.0 μU/mL ..........................................0.5-5.0 mU/L
Thyroidal iodine (123I) uptake.................................. 8%-30% of administered dose/24 h ...........0.08-0.30/24 h
Thyroxine (T4), serum ............................................. 5-12 μg/dL ................................................64-155 nmol/L
Triglycerides, serum ............................................... 35-160 mg/dL ............................................0.4-1.81 mmol/L
Triiodothyronine (T3), serum (RIA) ....................... 115-190 ng/dL ...........................................1.8-2.9 nmol/L
Triiodothyronine (T3) resin uptake.......................... 25%-35% ..................................................0.25-0.35
* Urea nitrogen, serum .............................................. 7-18 mg/dL ...............................................1.2-3.0 mmol/L
* Uric acid, serum ...................................................... 3.0-8.2 mg/dL ...........................................0.18-0.48 mmol/L
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LABORATORY VALUES (continued from previous page)
REFERENCE RANGE
SI REFERENCE INTERVALS
BODY MASS INDEX (BMI)
Body mass index .......................................................Adult: 19-25 kg/m2
CEREBROSPINAL FLUID
Cell count ..................................................................0-5/mm3 .............................................................0-5 x 106/L
Chloride ...................................................................118-132 mEq/L .................................................118-132 mmol/L
Gamma globulin .......................................................3%-12% total proteins .......................................0.03-0.12
Glucose ....................................................................40-70 mg/dL .....................................................2.2-3.9 mmol/L
Pressure ....................................................................70-180 mm H2O ...............................................70-180 mm H2O
Proteins, total ...........................................................