USMLE Step 1 vs. COMLEX Level 1: Category by Category

As you probably already know, the COMLEX Level 1 and USMLE Step 1 exams serve the same core purpose: to assess the fundamental medical knowledge necessary to advance to the third year of medical school for MD (USMLE) and DO (COMLEX) students. However, they differ quite dramatically in how they are written, what they emphasize, and how best to prepare for each one. 

In general, both exams test the fundamental knowledge of medicine that a third-year medical student should know, with a roughly equal distribution of questions on each body system. Level 1 does significantly emphasize the musculoskeletal/integumentary system more than Step 1, with 18% vs 6-10% of questions within this category, respectively. On top of that, 11% of Level 1 questions cover osteopathic manipulative medicine (OMM), the musculoskeletal treatment techniques for various injuries and diseases specific to DO trainees, which is obviously not covered on Step 1.

Another significant difference is the emphasis on basic science/biochemistry. Step 1 focuses 14-24% of the questions on “biochemistry and nutrition,” whereas Level 1 does not have a defined category or percentage listed. This difference is easily noticed on exam day and manifests as detailed biochemistry, genetics, organic chemistry, pharmacology, and scientific research questions on Step 1 that are not seen nearly as frequently on Level 1. For example, Step 1 may ask you to identify the specific gene or function involved, whereas Level 1 will more commonly ask for the diagnosis or first step in work-up.

Another broader difference reflected in the blueprint/content outline for each exam is the Level 1 emphasis on clinical care, including diagnosis, management, OMT, patient interaction, etc., compared to Step 1’s greater emphasis on physiology, pathophysiology, pathology, and basic science. This is a key difference to realize and keep in mind while preparing for each exam, as it should change where the focus lies when studying a given topic. This is not to say either exam will not test any of these categories, but rather to acknowledge the noticeable difference of emphasis and quantity of questions within each category.

Here are 5 things I would recommend when studying for each exam:

Written By: Dustin Dehart, DO | PGY II General Surgery, Chicago, IL