Board Exams for D.O. Students: COMLEX-USA Level 1, Level 2-CE and Level 3
The COMLEX-USA series for U.S. osteopathic students: what each level covers, how it is scored, eligibility, and how it relates to the USMLE.
Students at U.S. colleges of osteopathic medicine (COMs) take the COMLEX-USA series, developed by the National Board of Osteopathic Medical Examiners (NBOME). The series has three levels: Level 1, Level 2-CE and Level 3. They are taken in sequence, and each covers the osteopathic principles and practice that distinguish the D.O. curriculum alongside the core medical sciences. Many D.O. students also take the USMLE, which is a separate decision covered below. Details change, so confirm the current rules with the NBOME and your college.
The three levels
| Level | When it is usually taken | Format | Result |
|---|---|---|---|
| Level 1 | After the first year of study, commonly after the preclinical curriculum. | Two timed sessions of four hours each, with 320 single-best-answer multiple-choice questions. | Reported as pass or fail, not as a numeric score. |
| Level 2-CE (Cognitive Evaluation) | After the second year, usually during or soon after the clinical clerkships. | Four 3.5-hour sessions over two days, with 420 multiple-choice questions and about 26 clinical decision-making (CDM) cases. | Scored. The NBOME publishes the passing standard, with a score of 400 as the passing score. |
| Level 3 | After graduation, typically during early residency. | Two days, with two 3.5-hour sessions each day, and 420 multiple-choice questions plus about 26 CDM cases. | Scored. The NBOME publishes the passing standard, with a score of 350 as the passing score. |
The separate COMLEX-USA Level 2-PE (Performance Evaluation) clinical skills exam is no longer given. For Level 3 eligibility, your college dean attests to your clinical skills, or you may rely on a previous passing Level 2-PE result.
Eligibility in brief
- Level 1: completion of the first year at an accredited COM, with a good academic and professional standing attestation from your dean.
- Level 2-CE: a pass on Level 1, completion of the second year, and the same standing attestation.
- Level 3: passes on Level 1 and Level 2-CE, graduation from an accredited COM, a standing attestation from your residency program director, and a clinical skills attestation from your dean. The NBOME recommends completing about six months of graduate medical education first.
How to prepare
- Know the blueprint. The NBOME publishes content outlines for each level. Check how osteopathic principles and practice, including osteopathic manipulative treatment (OMT), are weighted, and plan time for them, since question banks built for other exams may cover them only lightly.
- Practice with realistic questions and CDM cases. Level 2-CE and Level 3 include clinical decision-making cases, so practice sequencing decisions as well as answering multiple-choice questions.
- Use official practice material. The NBOME and your college offer practice opportunities that show the format and pacing of a long testing day.
- Plan the dedicated block. A study block of several weeks with timed question blocks, careful review of every miss and a taper before test day works for most exams. See our Step 1, Step 2 CK and Step 3 preparation articles for a template you can adapt.
- Treat Level 1 as pass or fail. You do not need a high score, but a secure pass matters, and a failure can delay later levels.
COMLEX-USA and the USMLE
D.O. students and graduates may also take the USMLE. Many residency programs accept COMLEX-USA alone, but policies vary by program and specialty, and some applicants take both to widen their options, especially for competitive specialties or programs that publish a preference. Ask your college's advising office and check each program's requirements. Taking both is a substantial additional commitment, so decide early and plan the schedule.
Confirm the current rules
Format, scoring, passing standards, fees and eligibility are updated. Read the current information in the NBOME's COMLEX-USA pages and Bulletin of Information before you register. This article is general educational information for U.S. osteopathic students, not advice on your individual eligibility. See also our exam guides.
Educational content only. Confirm current exam requirements with USMLE.