COMLEX vs USMLE: Should DO Students Take Both?
DO students should decide whether to take USMLE by checking the requirements of their medical school and potential residency programs, then weighing readiness, time, and cost. Taking both examination series is not automatically right for every student. Neither is assuming that COMLEX alone will meet every program’s preferences.
Start with actual programs and decisions ahead of you. An online score-conversion chart cannot tell you whether a particular residency requires USMLE, and someone else’s successful application cannot settle your own school requirements.
Separate the exam pairs
COMLEX-USA is the osteopathic licensing examination series administered by NBOME. USMLE is sponsored by NBME and FSMB. Their content overlaps substantially, but their blueprints and score reporting are not identical.
| Stage | Osteopathic examination | USMLE examination | Important distinction |
|---|---|---|---|
| Foundational sciences | COMLEX-USA Level 1 | Step 1 | Both currently report pass/fail |
| Clinical knowledge | COMLEX-USA Level 2-CE | Step 2 CK | Both report numeric scores on different scales |
Step 1 changed to pass/fail reporting for examinations on or after January 26, 2022. COMLEX-USA Level 1 made that transition on May 10, 2022. Those dates matter when reading research from the era of numeric Level 1 and Step 1 scores. USMLE scoring information and NBOME scoring information
Do not treat the Step 1 decision as an automatic answer to the Step 2 CK decision. Review requirements for each examination separately and confirm current eligibility rules before building a timeline.
Check requirements before comparing resources
Make a small table of programs you might realistically apply to. For each one, record the application year, published COMLEX and USMLE requirements, whether a score is required before application or ranking, and the date you checked the information.
Distinguish “required,” “accepted,” and “preferred.” If wording is unclear, ask the program coordinator. Ask your school advisor how requirements interact with graduation, rotation, and examination policies. NRMP’s Program Director Survey describes factors reported by participating programs, but it does not replace an individual program’s current requirements. NRMP survey
| What you find | Next step |
|---|---|
| A target program explicitly requires a USMLE result | Confirm which Step, deadline, and preparation options |
| A program accepts either examination series | Discuss value and cost of an additional exam with an advisor |
| The website is silent or ambiguous | Obtain clarification before assuming acceptance or exclusion |
| Your school has a specific policy | Build that requirement into the plan before adding optional tests |
Why conversion formulas do not settle readiness
Older research found correlations between numeric COMLEX and USMLE scores. Correlation means scores tended to move together across a group; it does not make two scores interchangeable for an individual student. Sarko and colleagues studied 90 applicants to one emergency medicine residency and cautioned against treating examinations as interchangeable. Chick and colleagues likewise found associations with limits on individual prediction. These selected, pre-pass/fail samples do not provide a modern conversion rule. Sarko et al. and Chick et al.
A 2019 survey associated USMLE-oriented question-bank use with performance on both examinations. It was observational and cannot establish that a resource caused better results or that COMLEX-focused preparation is unnecessary. Jackson et al.
Plan for overlap and differences
Foundational science and clinical reasoning practice can support both examinations, but COMLEX includes osteopathic principles and practice. Compare preparation with current blueprints and identify what your main resource does not cover. Practice with both official interfaces if you plan to take both.
Current NBOME materials describe Level 1 as 320 questions over eight hours. Current Step 1 uses fourteen 30-minute blocks in an eight-hour testing session. Timing and navigation rules deserve separate practice even when content overlaps. NBOME examination descriptions and USMLE software update
There is no universal evidence-based rule that COMLEX must come first or that the examinations must be separated by one interval. Coordinate school deadlines, testing availability, readiness, and recovery time.
Count the whole cost
An additional exam costs more than registration. Include travel, subscriptions, practice assessments, scheduling changes, and the study time that could otherwise go toward rotations or required coursework. USMLE lists a $695 Step 1 application fee for 2026 and 2027, with additional region fees for eligible examinations outside the United States and Canada. Check the official application page for the fee and rules that apply to you. USMLE application information
Before committing to a second exam, confirm school requirements, program requirements or preferences, whether assessments support readiness for each examination, whether preparation fits health and finances, and what you will do if readiness or availability changes. Book a free consult to discuss the study side of your preparation timeline.