USMLE vs COMLEX: Key Differences and How to Prepare for Both

If you are a DO student, you have probably wondered whether to take both COMLEX and USMLE—and if so, how to prepare for two major board exams. This guide breaks down the key differences between the exams and provides strategies for students tackling both.

Understanding the Exams

COMLEX-USA

The Comprehensive Osteopathic Medical Licensing Examination is the board exam for osteopathic medical students. It is required for DO licensure and covers both standard medical content and osteopathic principles.

USMLE

The United States Medical Licensing Examination is the board exam for allopathic (MD) medical students. While not required for DO students, many choose to take it to demonstrate competitiveness for certain residencies.

Key Differences

Factor	COMLEX	USMLE
Required For	DO licensure	MD licensure
OMM Content	15-20% of exam	None
Question Style	Often longer stems, less polished	Concise, well-edited vignettes
Biostatistics	Present but less emphasized	More heavily tested
Answer Choices	Can include osteopathic treatments	Standard medical treatments
Scoring	Three-digit score, mean ~500	Pass/Fail (Step 1), scored (Step 2)

Should You Take Both?

This decision depends on your career goals:

Take Both If:

• You are interested in highly competitive specialties (dermatology, orthopedics, plastic surgery)
• You want to keep all residency options open
• You are applying to residencies at MD-majority institutions
• Your school supports and prepares students for both exams

COMLEX Only If:

• You are pursuing primary care or less competitive specialties
• You are applying primarily to osteopathic or DO-friendly programs
• Your schedule cannot accommodate preparation for both
• You struggle with standardized testing and need to focus resources

Content Overlap

The good news: approximately 80-85% of the content overlaps. Core medical knowledge—pathology, pharmacology, physiology—is tested similarly on both exams. Your primary preparation resources work for both.

COMLEX-Specific Content

• Osteopathic manipulative medicine (OMM/OMT)
• Osteopathic philosophy and principles
• Chapman points and viscerosomatic reflexes
• Cranial osteopathy basics

USMLE-Specific Emphasis

• Biostatistics and epidemiology (more depth)
• Ethics and medicolegal topics
• Certain pathophysiology details

Preparation Strategy for Both Exams

If you are taking both, efficiency is essential. Here is a strategic approach:

Build a Shared Foundation

Use standard resources that cover both exams:

• First Aid: The core framework for medical content
• UWorld: Best question bank, essential for USMLE and helpful for COMLEX
• Pathoma: Pathology foundation
• Sketchy: Microbiology and pharmacology

Platforms like MedSchool Companion help by generating practice questions from your school's content, ensuring you cover both the standard medical curriculum and any osteopathic material included in your lectures.

Add COMLEX-Specific Resources

Supplement your base preparation with OMM-focused materials:

• COMBANK: COMLEX-style questions with OMM content
• Savarese OMM Review: The standard OMM reference
• School OMM resources: Your program's OMM curriculum

Practice Question Strategy

• Complete UWorld thoroughly—this is your primary resource
• Add COMBANK for COMLEX-style practice and OMM questions
• Do timed blocks under realistic conditions for both exam types
• Review all explanations carefully

Scheduling Both Exams

Timing matters significantly:

Option 1: COMLEX First

Take COMLEX first, then USMLE 1-2 weeks later.

Pros: Peak knowledge for the required exam; USMLE feels easier after COMLEX-style questions

Cons: Need to maintain momentum for second exam

Option 2: USMLE First

Take USMLE first, then COMLEX 1-2 weeks later.

Pros: USMLE is often considered more straightforward; more time to review OMM

Cons: Risk performing worse on the required exam

Most Common Approach

Most successful students take COMLEX first. It is the required exam, and the additional OMM content means COMLEX-specific preparation is more substantial than adding biostatistics review for USMLE.

Managing OMM Preparation

OMM can feel overwhelming, but it is manageable:

Start Early

Do not cram OMM. Begin regular review early in your dedicated period.

Focus on High-Yield

• Somatic dysfunction diagnosis criteria
• Contraindications for techniques
• Viscerosomatic reflexes
• Chapman points for common conditions
• Cranial mechanism basics

Use Visual Learning

OMM techniques are easier to understand visually. Watch videos, practice on classmates, and visualize during review.

During Dedicated Study Period

A typical schedule for dual preparation:

Weeks 1-4

Focus on shared content. Complete UWorld systematically. Review First Aid. Minimal OMM (just maintaining baseline).

Weeks 5-6

Increase OMM focus. Start COMBANK. Continue UWorld review of incorrect questions.

Week 7

Heavy OMM review. COMLEX practice exams. Light medical content review.

Exam Week 1

Take COMLEX. Brief rest. Resume medical content review.

Exam Week 2

Final USMLE preparation. Focus on biostatistics and any weak areas. Take USMLE.

Mental Preparation

Taking two board exams is demanding. Protect your mental health:

• Accept that some fatigue between exams is normal
• Maintain sleep, exercise, and social connection
• Celebrate completing COMLEX before diving back into study mode
• Remember that thousands of DO students successfully complete both exams every year

After the Exams

Both exams are pass/fail or scored depending on the level. For residency applications:

• Report both scores if they are competitive
• If one score is significantly lower, consider whether to report it
• USMLE scores may carry more weight at MD programs, but strong COMLEX scores are valued at DO-friendly programs

Resources Summary

For Both Exams:

• First Aid, UWorld, Pathoma, Sketchy
• AI-powered platforms like MedSchool Companion for custom practice questions
• NBMEs (USMLE) and COMSAE (COMLEX) practice exams

COMLEX-Specific:

• COMBANK, Savarese, school OMM resources

USMLE-Specific:

• Additional biostatistics review if needed

Final Advice

The decision to take both exams is significant, but it is manageable with proper planning. Focus on building a strong foundation in core medical knowledge, add targeted OMM preparation, and schedule your exams strategically.

Whether you take one exam or both, success comes from consistent preparation, active learning methods, and taking care of yourself throughout the process. You are capable of this—now go make it happen.