USMLE Step 1 Blood and Immune Practice Questions
9–13% of Step 1 · 36 practice questions with a note on every option
280 questions in 14 timed 30-minute blocks, with your score in blood and immune and every other content area.
Free blood and immune drillA 4-year-old boy is brought to the physician because of fever and right upper quadrant pain. He has had recurrent skin abscesses and suppurative cervical lymphadenitis since infancy and was treated for Aspergillus pneumonia last year. CT shows a liver abscess, and drainage grows Staphylococcus aureus. Immunoglobulin levels and lymphocyte subsets are normal. Neutrophils stimulated in a dihydrorhodamine flow cytometry assay show no increase in fluorescence. A defect in which of the following is most likely?
Blood & Lymphoreticular/Immune Systems on Step 1
Blood & Lymphoreticular/Immune Systems is 9–13% of Step 1. Questions start from a blood count, a smear or a reaction and ask for the mechanism: the enzyme that is missing, the cell that is responsible, or the drug that acts on that pathway.
- Share of Step 1
- 9–13% of the exam, per the USMLE content outline
- On our mock exam
- 30 of 280 questions, with your score for this system in the result
- Our drill
- 10 questions from 36 blood and immune questions, untimed, a note on every option; one free attempt, unlimited with a pass
What Step 1 blood and immune questions test
- Anemias by MCV and mechanism: iron deficiency, thalassemia, B12 and folate deficiency, hemolysis and G6PD deficiency
- Hemostasis: the coagulation cascade, platelet disorders, von Willebrand disease, hemophilia, DIC and thrombophilia
- Leukemias, lymphomas, myeloma and their characteristic translocations
- Immunodeficiencies, hypersensitivity types I–IV, transplant rejection and the complement system
- Pharmacology: heparin, warfarin, direct oral anticoagulants, antiplatelet drugs, thrombolytics and chemotherapy toxicities
Sit all 280 questions in timed blocks
280 questions in 14 timed 30-minute blocks, with your score in blood and immune and every other content area.
Free blood and immune drillHow to study it
- Draw the coagulation cascade once and mark where each drug and each lab test acts.
- Sort anemias by MCV and reticulocyte count before you memorize causes.
- Pair each immunodeficiency with the cell or protein that is missing and the infections it causes.
Common questions
Are blood smear images on Step 1?
The real exam shows images. Our practice questions describe smears and stains in words, so learn the findings by name: target cells, schistocytes, Auer rods, Reed-Sternberg cells.
How much immunology is on Step 1?
Immunology is listed at 5–15% of Step 1 as a discipline and runs through every system. Most of it sits in this category: hypersensitivity, immunodeficiency and transplant questions.
280 questions in 14 timed 30-minute blocks, with your score in blood and immune and every other content area.
Free blood and immune drillThe other Step 1 systems
Sources
- USMLE: Step 1 (blocks, items, testing day, break time)
- USMLE: Step 2 CK (blocks, items, testing day, break time)
- USMLE: Test delivery software updates for Step 2 CK and Step 1 (May 2026)
- USMLE: Step 1 content outline and specifications
- USMLE: Step 2 CK content outline and specifications
- USMLE: Examination results and scoring (minimum passing scores)
- USMLE Bulletin: Scoring and score reporting (about 60% correct to pass; result timing)
- USMLE Bulletin: Eligibility (attempt limits)
- USMLE: Apply for exams (2026 and 2027 fees, FSMB registration, region fees)
- USMLE: Performance data (pass rates)
- Intealth ECFMG: Fees overview (ECFMG Certification)
Original practice questions written to the USMLE content outlines and current standard references. USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and NBME. Independent practice, not affiliated with or endorsed by the FSMB, NBME or Intealth (ECFMG). Follow current guidelines in clinical practice.