The best way to prepare for USMLE® Step 1 is to practice with questions that mirror the real exam. Step 1 relies on patient-centered clinical vignettes in a single-best-answer format; the only way to get comfortable with that style is repetition. Below you will find sample questions with detailed explanations, followed by a guide to every worthwhile free Step 1 resource available in 2026.
Important for 2026 test-takers: Starting May 14, 2026, the Step 1 format changes to 14 blocks of 20 questions (30 minutes each), replacing the current 7 blocks of 40 questions (60 minutes each). Total questions and testing time stay the same. More on this below.
Sample Step 1 Practice Questions With Explanations
These questions follow the NBME clinical vignette format. Each presents a patient scenario and asks you to identify the single best answer.
Question 1: Pharmacology
A 58-year-old man with type 2 diabetes and chronic kidney disease (eGFR 25 mL/min/1.73 m²) presents for medication review. His current HbA1c is 8.9%. He takes metformin 1,000 mg twice daily and sitagliptin 50 mg daily. Which of the following changes to his regimen is most appropriate?
- A. Increase metformin to 1,500 mg twice daily
- B. Add pioglitazone
- **C. Discontinue metformin** ✓
- D. Add empagliflozin
- E. Switch sitagliptin to glyburide
Explanation: Metformin should be discontinued when eGFR falls below 30 mL/min/1.73 m² because of the risk of lactic acidosis. This patient’s eGFR of 25 makes continued metformin use unsafe; it must be stopped regardless of glycemic control. Increasing the dose (A) would compound the risk.
Pioglitazone (B) can be used in CKD but carries fluid retention risk and does not address the contraindicated medication. Empagliflozin (D) has minimal glycemic benefit at this eGFR level. Glyburide (E) is inappropriate in severe renal impairment because its active metabolites accumulate and cause prolonged hypoglycemia. Sitagliptin at 50 mg is already appropriately dose-adjusted for this GFR range and can be continued.
Tested concept: Renal contraindications for metformin and medication management in CKD.
Question 2: Pathology
A 35-year-old woman presents with fatigue, weight gain, and cold intolerance over the past 6 months. Physical examination reveals dry skin, periorbital edema, and delayed relaxation of deep tendon reflexes. Laboratory studies show elevated TSH and low free T4. A fine-needle aspiration of her enlarged thyroid shows lymphocytic infiltration with germinal center formation. Which of the following antibodies is most likely to confirm the diagnosis?
- A. Anti-TSH receptor antibody (stimulating)
- B. Anti-thyroglobulin antibody
- **C. Anti-thyroid peroxidase (anti-TPO) antibody** ✓
- D. Anti-smooth muscle antibody
- E. Anti-nuclear antibody
Explanation: The clinical picture — hypothyroidism with lymphocytic infiltration and germinal centers on biopsy — is classic for Hashimoto thyroiditis. Anti-TPO antibodies are the most sensitive and specific serologic marker, present in roughly 90–95% of Hashimoto patients.
Anti-TSH receptor stimulating antibodies (A) point to Graves disease, which causes hyperthyroidism. Anti-thyroglobulin antibodies (B) can be positive in Hashimoto disease but are less sensitive than anti-TPO. Anti-smooth muscle antibodies (D) are associated with autoimmune hepatitis, not thyroid disease. ANA (E) is nonspecific and not diagnostic here.
Tested concept: Autoimmune thyroiditis and associated autoantibodies.
Question 3: Physiology
A researcher is studying oxygen delivery in healthy volunteers at sea level. She measures the partial pressure of oxygen in the alveoli (PAO2) and in arterial blood (PaO2). Under normal conditions, which of the following best explains why PaO2 is slightly lower than PAO2?
- A. Oxygen consumption by alveolar epithelial cells
- **B. Physiologic shunting through bronchial and Thebesian venous drainage** ✓
- C. Diffusion limitation across the alveolar membrane
- D. Ventilation-perfusion mismatch in the lung apices
- E. Increased dead space ventilation
Explanation: The normal A-a gradient (roughly 5–15 mmHg in young adults) exists primarily because of physiologic shunting. Deoxygenated blood from the bronchial circulation and the Thebesian veins drains directly into the left heart, mixing with fully oxygenated pulmonary venous blood and slightly lowering PaO2.
Diffusion limitation (C) does not occur at rest in healthy individuals at sea level. V/Q mismatch (D) is present to a small degree due to gravity, but the dominant contributor to the normal A-a gradient in healthy lungs is anatomic shunt. Dead space ventilation (E) affects CO2 elimination, not the A-a oxygen gradient.
Tested concept: Alveolar-arterial oxygen gradient and physiologic shunt.
Want to practice more? Use Lecturio’s Qbank with over 2.200 Step 1 practice questions!
What Changes for Step 1 in May 2026?
On May 14, 2026, the USMLE rolls out updated test delivery software. Content and total question count stay the same; the block structure changes:
| Feature | Current (through May 13) | New (from May 14) |
| Blocks | 7 | 14 |
| Questions per block | Up to 40 | Up to 20 |
| Time per block | 60 minutes | 30 minutes |
| Total questions | Up to 280 | Up to 280 |
| Total testing time | ~8 hours | ~8 hours |
Shorter blocks may help with focus and fatigue management; you get natural break points twice as often. The updated software also adds improved keyboard navigation, image contrast settings, and a refreshed interface.
If you are scheduling around this date, there is no reason to rush. The exam is not harder or easier under the new structure.
Best Free Step 1 Practice Resources
Not every resource is worth your time. Here is what is actually available for free in 2026, organized by depth of access.
Tier 1: Substantial Free Question Banks
Lecturio — 1,000+ free questions The largest free Step 1 Qbank available without a credit card. Questions include video-integrated explanations, First Aid cross-references, and adaptive performance tracking. The free tier covers all major subject areas with enough volume for meaningful practice. Full Qbank: 2,200+ questions starting at $19.99/month. Start free practice
USMLE Free 120 — Official Practice The only official Step 1 sample questions released by the USMLE program. Available via the USMLE website, this 120-question set is essential for every student. It provides the most accurate preview of the actual software interface, question style, and pacing you will encounter on test day.
Public Medical Libraries & Open Question Sets Several medical database platforms offer high-volume question libraries with organ-system classifications. While the user interfaces on these “freemium” platforms can be less polished than dedicated prep apps, they serve as a solid supplement for extra practice on specific niche topics.
Tier 2: Supplementary Learning Tools
Official NBME Self-Assessments (Paid): While not free, these are the most predictive tools available for estimating your actual performance. We recommend budgeting for at least two official self-assessments in your final month of “dedicated” study to ensure you are safely above the passing threshold.
Digital Flashcard Systems (Spaced Repetition): Using digital flashcard decks is the most popular way to build long-term retention. Community-curated decks containing 30,000+ cards cover the entire Step 1 curriculum. By utilizing spaced-repetition software, you can ensure that the facts you learn in your Qbank stay in your memory until test day.
How to Build a Practice Routine That Works
Access to thousands of questions does not help without structure.
Start with a baseline. Take the USMLE-Rx self-assessment or a single NBME form before beginning dedicated study. This tells you where you stand and which subjects need the most attention.
Commit to one primary Qbank. Pick Lecturio or StatPearls as your main free resource and work through it systematically. Jumping between platforms gives you breadth without depth. Save a paid option like UWorld or AMBOSS for closer to your exam date if budget allows.
Review every explanation; especially when you guessed right. A correct guess is not knowledge. The explanation cements the reasoning pattern the exam is actually testing.
Track performance by subject. Most platforms — including Lecturio’s free tier — offer performance dashboards. If you are at 45% in pharmacology but 75% in anatomy, reallocate your study hours accordingly.
Simulate real test conditions at least twice. Before your exam, sit through a full timed session with all blocks, a real break schedule, and no phone. Many students are surprised by how much fatigue affects their accuracy in the later blocks.
Complete the Free 120 last. Save the official USMLE questions for the final one to two weeks. They set your expectations for difficulty better than any third-party resource.
Lecturio’s Step 1 Qbank includes over 1,000 free practice questions with video explanations and First Aid cross-references. No credit card required; no time limit. Start practicing for free.
FAQs: Step 1 Practice Questions
How many practice questions should I do before Step 1?
Most students who pass comfortably complete 2,000–3,000+ questions during dedicated study. Quality matters more than quantity; reviewing rationales is where the real learning happens.
Is Step 1 still important now that it is pass/fail?
Yes. You must pass to progress to Step 2 CK and residency applications. Failing can significantly delay your timeline due to retake eligibility rules and scheduling. While numerical scores no longer differentiate candidates, the knowledge tested on Step 1 is the foundation for clinical rotations and Step 2 CK preparation.
Are the free questions as good as paid ones?
Lecturio’s free questions come from the same Qbank used by paying subscribers; they are not watered down. The Free 120 is written by NBME itself. Paid platforms may have more polished explanations for certain topics, but free resources are sufficient to pass.
Should I use flashcards alongside a Qbank?
Strongly recommended. Qbanks test application; flashcards build long-term retention. Start using flashcards early in preclinical years and layer in Qbank practice during dedicated study.
