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For DO students · Taught by a DO
COMLEX Level 2 vs Step 2 CK
The two clinical exams side by side, from NBOME and USMLE, and how to prepare if you are taking both.
Book a free intro consultationFree intro consultation: a 20-minute phone call.
DO students can take COMLEX Level 2-CE, USMLE Step 2 CK, or both. The two exams test clinical knowledge on different terms: different length, different scales, different passing scores, and osteopathic content on only one of them. Below is a side-by-side from NBOME and USMLE, with every cell linked to its source.
We tutor both exams. The Boards Professor is led by Dr. Shauhin “Sean” Moazezi, DO, a board-certified internist who trained at an osteopathic medical school, took the COMLEX himself and teaches full time.
Side by side
Figures as published by NBOME and USMLE. Numbers in brackets link to the source list below.
| COMLEX Level 2-CE | USMLE Step 2 CK | |
|---|---|---|
| Who can take it | Students at a COCA-accredited college of osteopathic medicine who have passed Level 1 and completed second year [4] | MD students and graduates (LCME), DO students and graduates (COCA), and eligible international students and graduates [8] |
| Why it matters | NBOME: passing is “required to enter into supervised graduate medical education settings” [1] | A Step in the USMLE sequence; you must meet USMLE eligibility requirements to sit it [5][8] |
| Length | 8 hours: two timed sessions of four hours each, on one day [2] | 9 hours: one testing session, on one day [5] |
| Number of questions | 320 single-best-answer questions: 8 sections of 40 [2] | From May 7, 2026: sixteen 30-minute blocks of up to 20 questions each [5] |
| Score | Three-digit standard score plus a pass/fail designation [3] | Three-digit score scale with a pass/fail result [9] |
| Passing score | 400 [3] | 218, for exams on or after July 1, 2025 (was 214) [6] |
| Osteopathic content (OMM) | At least 10% of the exam: Domain 1, Osteopathic Principles, Practice, and Manipulative Treatment [1] | Not listed in the Step 2 CK content outline [7] |
| Results | Usually within two to six weeks [1] | Typically two to four weeks after your test date [9] |
| Attempt limits | Four scored attempts per level, and no more than four in any 12 months [4] | No more than three in any 12 months; four attempts without a pass ends eligibility for any Step [8] |
Can you convert a COMLEX score to a Step 2 CK score?
Not officially. None of the NBOME or USMLE pages in our source list publish a conversion from a Level 2 score to a Step 2 CK score, and the two exams set different passing scores (400 and 218). Conversion charts you see online are unofficial estimates, so we do not use them.
Which should a DO student take?
That depends on your school’s requirements and the programs you are applying to, so check both. What the official rules do say: NBOME describes passing Level 2-CE as required to enter supervised graduate medical education, and USMLE lists DO students at COCA-accredited schools as eligible for Step 2 CK. If you take both, plan your dates around both sets of attempt rules in the table.
Studying for both
- Shared core. Both test clinical knowledge, so much of your question practice serves both.
- COMLEX only. Osteopathic principles and OMM are at least 10% of Level 2-CE, so they need their own time.
- Different exam day. On test day, Level 2-CE is two 4-hour sessions; Step 2 CK is one 9-hour session in 30-minute blocks.
See COMLEX tutoring and USMLE Step 2 CK tutoring for how sessions work.
COMLEX vs Step 2 CK FAQ
Is COMLEX Level 2-CE harder than USMLE Step 2 CK?
Neither NBOME nor USMLE compares difficulty. The exams differ in length (8 hours vs 9 hours), passing score (400 vs 218) and osteopathic content, which is at least 10% of Level 2-CE.
Can I convert my COMLEX Level 2-CE score to a Step 2 CK score?
Not officially. We found no conversion published by NBOME or USMLE. Charts online are unofficial estimates.
Can DO students take USMLE Step 2 CK?
Yes. USMLE lists students and graduates of U.S. DO programs at COCA-accredited schools as eligible for Step 2 CK.
What is the passing score for each exam?
NBOME lists 400 as the passing score for Level 2-CE. USMLE set the Step 2 CK passing score at 218 for exams on or after July 1, 2025.
Do you tutor both COMLEX Level 2-CE and Step 2 CK?
Yes. We tutor both, one-on-one online over Zoom, including osteopathic principles and practice. Book a free intro consult, a 20-minute phone call.
Sources
- NBOME: COMLEX-USA Level 2-CE
- NBOME: Examination format
- NBOME: Scoring and reporting
- NBOME: Bulletin of Information, eligibility
- USMLE: Step 2 CK
- USMLE: Change to the Step 2 CK passing standard (July 1, 2025)
- USMLE: Step 2 CK content outline and specifications
- USMLE: Eligibility requirements
- USMLE: Scoring and score reporting