I can’t recommend Sean enough. After failing my first Step 1 attempt, I felt overwhelmed, discouraged, and unsure of how to move forward while balancing medical school with family life as a husband and father of two. Sean quickly recognized exactly what I needed: not more content, but a better way to apply what I knew. He built a tailored plan for me and taught me a systematic approach to breaking down and attacking questions that completely transformed my performance. That structure, along with his energy, accountability, and encouragement, helped me rebuild my confidence and start passing NBME practice exams consistently. Sean is more than a great tutor — he’s an outstanding mentor and an exceptional person. If you’re struggling with Step 1 or trying to come back from a setback, he is absolutely the person you want by your side!
Everything about the exams themselves on this page comes from NBME and USMLE, linked where it is stated, and was checked on October 13, 2026. The study advice is Dr. Shauhin “Sean” Moazezi’s, quoted from his tutoring sessions; it is general, and your own plan is set with your tutor.
What are NBME practice exams?
They are the NBME Self-Assessments, practice exams written by NBME, which co-sponsors the USMLE. NBME lists them by exam: the Comprehensive Basic Science Self-Assessment is for students taking Step 1, and the Comprehensive Clinical Science Self-Assessment is for Step 2 CK. NBME says the questions are created “with the same quality and statistical rigor as the USMLE” (NBME, Step 1 self-assessment). After you finish one, the score report gives your estimated probability of passing and an equated percent correct score (ECP) by content area. NBME is clear that the estimate is not a promise of how you will do on Step 1.
How many NBMEs are there for Step 1?
Seven. NBME’s page for the Comprehensive Basic Science Self-Assessment says you can “select one or multiple of seven available” forms (NBME, Step 1 self-assessment).
How many Step 2 CK NBMEs are there?
Also seven. The Comprehensive Clinical Science Self-Assessment page says “select one or multiple of seven available” forms (NBME, Step 2 CK self-assessment).
NBME practice exams for Step 2 CK
For Step 2 CK the NBME form is the Comprehensive Clinical Science Self-Assessment (CCSSA): seven forms, from $62, each four sections of 50 questions, and a score report with an estimated probability of passing and a lookup to the USMLE score scale (NBME CCSSA; NBME self-assessment FAQ). With the Step 2 CK passing score at 218, the estimate matters less than the margin: we look for several forms in a row comfortably above the score you are aiming for.
A common sequence over a six-week dedicated period is one form as a baseline before week 1 and then one every week or two, ending about a week before the exam. Which forms to take first is covered in which NBME to take first, and the free USMLE practice set in our Step 2 CK Free 120 guide. If you are aiming at a competitive specialty, set the target from the Step 2 CK scores by specialty table, not from 218.
NBME practice exams for Step 3
For Step 3, NBME sells the Comprehensive Clinical Medicine Self-Assessment (CCMSA): multiple forms, each 200 questions in four sections of 50, at $62 (NBME CCMSA). Like the other self-assessments it is bought and taken through the MyNBME examinee portal. It covers the multiple-choice side of the exam only, so pair it with the free Step 3 interactive testing experience and practice CCS cases that USMLE publishes (USMLE Step 3 practice materials). The Step 3 passing score is 200.
| Exam | NBME practice test | Forms | Questions | Price |
|---|---|---|---|---|
| Step 1 | Comprehensive Basic Science Self-Assessment (CBSSA) | 7 | 200 (4 x 50) | from $62 |
| Step 2 CK | Comprehensive Clinical Science Self-Assessment (CCSSA) | 7 | 200 (4 x 50) | from $62 |
| Step 3 | Comprehensive Clinical Medicine Self-Assessment (CCMSA) | multiple | 200 (4 x 50) | $62 |
| Shelf exams | Clinical Science Mastery Series, by discipline | multiple per discipline | 50 | $21 |
How long are NBME practice exams?
In standard-paced mode, NBME allows 1 hour and 15 minutes for each of four sections of 50 questions, which is 5 hours of testing time in total (NBME, Step 2 CK self-assessment). The Step 1 page states 1 hour 15 minutes per Comprehensive Basic Science block (NBME, Step 1 self-assessment). If you choose self-paced mode when you order, each section gets 5 hours instead, four times as long.
How do you purchase NBME practice exams?
Through the MyNBME Examinee Portal: each self-assessment page on nbme.org has a “Buy Now” button, and NBME lists the price as starting at $62 (NBME, Step 1; NBME, Step 2 CK). You pick standard-paced or self-paced timing when you order. NBME says you can take them anywhere you have a suitable computer with internet, and after finishing you can review every question, the correct answers and the explanations for 2 years. These are not the same as the practice sessions at Prometric test centers, which can only be booked once you have your USMLE registration permit and use the USMLE sample questions.
What is the free 120?
It is the name students use for the sample test questions USMLE publishes. USMLE says “more than 100 sample” questions are available for each exam, as a PDF and as an interactive testing experience (USMLE, Step 1 sample questions; USMLE, Step 2 CK sample questions). Sean suggests taking it about three days before your exam: “The free 120, you want to take about three days before…”
How Sean uses NBME practice exams
Sean treats practice tests as the main measure of progress. The usual rhythm he sets is one a week:
“All you gotta do is you take a practice test once a week, you know.”
Sean, tutoring session, October 2, 2026
Close to the exam, the pace goes up. Talking to a student with a test date ahead, he said:
“In that last week, what I recommend doing is taking it about every three days.”
Sean, tutoring session, October 7, 2026
and, on the order of the remaining tests, “save the free 120 for the last three days.”
Reading the score
Sean’s point is that a full practice test is the best data you get, because it covers so many questions:
“You’ve had a very good sample size, which means the data that you get from this has good power.”
Sean, tutoring session, October 12, 2026
So the score report decides what to study next. NBME reports performance by content area (NBME), and Sean starts from the weakest systems:
“To start, you should be thinking of the three systems that were your lowest on your last practice test.”
Sean, tutoring session, September 25, 2026
Those focus areas then hold until the next test: “your systems will stay stable until you reassess with a new practice test.”
Review it the same day
Sean’s rule is to go through the test the day you take it, while it is still fresh. NBME keeps the questions and explanations available for 2 years (NBME), but what you were thinking when you chose an answer does not last that long. For his other answers on practice tests, Anki and daily question volume, see the questions students ask Sean most.
NBME practice for shelf exams
For clerkship shelf exams, NBME sells the Clinical Science Mastery Series: forms of 50 multiple-choice questions for Clinical Neurology, Emergency Medicine, Family Medicine, Medicine, Obstetrics and Gynecology, Pediatrics, Psychiatry and Surgery. Each form costs $21 and can be taken under standard timing (1 hour 15 minutes) or self-paced (5 hours), and you have one year to complete it.
Its score report includes a conversion table that estimates your subject exam score, answer explanations for every item, and longitudinal feedback when you take more than one. See our shelf exam tutoring for how we use them during rotations.
Are NBME shelf practice exams available as PDFs?
Not from NBME. The Clinical Science Mastery Series, like all NBME self-assessments, is sold through the MyNBME examinee portal and taken online on any computer with an internet connection (NBME self-assessment FAQ). You have a year from purchase to complete a form (NBME Mastery Series). Once you finish, you can review every question with its answer explanation and print your performance profile, and both stay available for two years.
Can you retake NBME practice exams?
You can buy and sit a form you have taken before: NBME's INSIGHTS tool is built to show trends "across multiple takes of the same exam" (NBME). A repeat score overstates your readiness, though, because you have already seen the questions and their explanations. Use repeats for review, and use a form you have never seen when the score has to decide something, like your test date.
Official practice from USMLE itself
Alongside NBME's paid self-assessments, USMLE publishes free preparation materials for each Step: sample questions in the exam's formats and an interactive testing experience, including new versions for the 2026 formats. They are the best way to practise the real interface, especially the shorter 30-minute blocks that Step 1 and Step 2 CK use from May 2026.
Practice scores and the passing line
Practice exams estimate your score; they cannot promise it. For scored exams, compare your practice results with the current passing standard (218 for Step 2 CK and 200 for Step 3, per USMLE) and look for a steady margin, not one good result.
When to take each practice exam
We spread practice exams through a study period rather than bunching them at the end. An early one gives a baseline and shows where to spend time; the middle ones show whether the plan is working; the last ones, close to the test date, decide whether to keep the date or move it.
Take them under real conditions: timed, in one sitting, at the block length of the real exam. A practice exam taken in pieces or with breaks the real exam does not allow gives you a number that is hard to trust.
What to look at in the score report
Look past the single number. Check which content areas fell furthest below the rest, compare them with your question bank data, and note whether misses cluster at the end of blocks, which points to timing. Those three readings tell you what to change before the next practice exam.
If two practice exams in a row point to the same weak areas, that is the clearest signal you will get about where the next weeks should go.
We go through every practice exam with you in a session. One-on-one tutoring is $349 per 50-minute session by live video (Zoom or Google Meet), and the first 20-minute intro consult is free.