COMLEX Level 3 Overview

2 months for Step 1

2 weeks for Step 2

#2 Pencil for Step 3

This is the mantra that has been whispered among medical students regarding how long to prepare for each board exam. While I only had 1 month of time for dedicated Level 1 studying, I spent the 4 months leading up to boards reviewing my weakest subjects. My school also afforded us a whole month off of rotations to prepare for Level 2 between our 3rd and 4th year. So when it came to Level 3 I knew I didn’t feel comfortable just *winging it*. The biggest obstacle preparing for Step 3/Level 3 is how busy intern year can be juggling long work hours, call, and education requirements of the resident program.

In total I spent about 3 months preparing for Level 3. The reason I spaced out my study schedule the way I did was because the rotation I was on leading up to my boards had me taking home call every night. As I never had guaranteed nights off I set bare minimum goals for my daily studying (1 Lecture, 10 questions, etc.).


Per the NBOME: “The examination consists of four computer-based test sessions of 3.5 hours each, taken over two days (two sessions per day) and is administered within a 14-day window in a secure, time-measured environment. The exam contains approximately 420 questions in the multiple choice question (MCQ) format and test questions related to approximately 26 clinical decision-making cases.”

The Clinical Decision-Making cases is a new change for Level 3 as of September 2018. Before September 2018, Level 3 was a one day test, similar to COMLEX Level 1 and Level 2-CE composed of multiple choice questions. Now COMLEX Level 3 is split into 2 days. Day 1 is 4 sections of 70 multiple choice questions and day 2 is 2 sections of 70 multiple choice questions and 2 section of 13 clinical decision making cases.

CDM cases are comprised of multiple choice and short answer questions. The multiple choice questions can be a variety of selecting 1-4 responses per each question. Each section contained 13 cases and a total of 37 questions. After answering a question and clicking submit your answer choice would be locked for you to progress to the next portion of the case. (for a more descriptive explanation of the format of the CDM cases scroll down to the review of UWorld in the resources section of this post)


When to take it

If you take nothing else from this blog post, please head this advice: Take Level 3 as soon as you can. The reasoning for this is two-fold.

#1: Unless you are in a primary care residency you will forget

As I started my board prep studying I encountered a fetal heart rate monitor reading and was required to interpret the results. Looking at the image, I racked my brain to remember what late decelerations indicated and what the recommendations were. As I went through my OBGYN question sets I realized that while every topic sounded familiar I had a hard time remembering the information I needed to answer the question. I realized that even though it had only been a year since I completed my core rotations I had forgotten a lot of the basics. I’m glad I took Level 3 during the first portion of intern year. I debating delaying the test hoping to take it during an “easier” rotation or one when I wouldn’t be on call as frequently, but in intern year there are no guarantees as to when you may be done with work or how much down time you will have to study. Let time be on your side and take the test as early as you can (preferably before intern year begins) so you can get it out of the way and focus on the requirements of your residency program.

#2: All the testing dates fill up fast!

As Level 3 is now a two day exam, unless you are fortunate enough to have a Prometric site near your hospital, it is a logistic nightmare trying to coordinate two separate days off, two travel days and two separate stays in a hotel. I took my two test days back to back and I highly recommend it. Although my brain was pretty much mush at the end of Day 2, it was a relief knowing that if I just powered through my studying and focused for the 2 days of testing it would be over soon. My fellow residents and attendings also did their best to allow me time to study leading up to my boards and I don’t know if they would’ve been able to adjust the schedule like they did for me to be absent two separate times.

Scheduling the exam:

Another change as of September 2018, is that a candidate is required to have an attestation completed by a residency program director that a candidate is in good academic and professional standing in an AOA- or ACGME-accredited residency program. If you are hoping to take your Level 3 in June before intern year officially begins you will have to coordinate with your program coordinator or program director to have your attestation completed prior to you starting at their program. After the attestation is complete you can go through the sign up process on NBOME and Prometric as you did for Level 1 and Level 2.

The cost for Level 3 is $875

How to Study

Now I have to preface that I do not yet have my level 3 score, so I cannot say if my study plan was effective or not. I can however give my opinion on how adequately prepared I felt for the exam based off the resources I used. I will also preface this section by saying I went totally overboard in preparing for this exam. As a general rule, a question bank is your best preparation for this exam. Being a busy intern, it was hard to carve out time to watch review lectures or to read a couple pages of a reference textbook. If I had to do this process all over again, I would focus my studying solely on a question bank, and save myself the headache and the money that came with juggling all the resources I purchased.

DIT Step 3

I had used DIT for my Step 1 preparations and I had loved it. I thought their lectures covered the high yield topics in depth enough, while being concise enough to

DIT for Step 3 is compiled of two parts. Part 1 is the “Clinical Questions” section which is arranged by specialty. Each video asks 10 open ended clinical question and then provides the answer. I truthfully did not complete many videos in this section because I didn’t find the format to be beneficial for me. Unlike DIT lectures where they give helpful mnemonics or describe a process in depth, this was just basically lists of  things you have to remember (labs to order for a specific disease process, medications to discharge someone home on after COPD exacerbation, etc.)

Part 2 was the video series, most similar to the DIT from Step 1 that I remember. It is composed of 27 videos covering the most commonly tested clinical topics. With your DIT subscription you have 45 days to access this portion of your subscription, which is about 10 hours’ worth of video lectures. They also have a video that discusses strategies to pass the computer-based case simulations (CCS).

In all honesty I decided to purchase DIT for Step 3 mainly because of its “low” price point at $249 (a huge discount compared to the $825 for DIT Step 1) and because I thought video series would be a way to passively learn when my brain was too fried from a long day. While I think the video series portion of this subscription was helpful, I don’t think I would recommend using DIT Step 3 as a resource for this test. My reasoning for this is lack of dedicated study time as an intern. While it was easy for me to do a quick question set on Combank or UWorld between patients, I didn’t find much time that allowed me to sit at a computer with my headset on and be ready to take notes in my DIT workbook. I think if you learn best from listening to someone else, the videos in here are high yield, however I think this content can be found in other free video resources like Online Med Ed


Every osteopathic student/physician has had the struggle in deciding between getting the gold standard board preparation question bank (UWorld) or to focus on an osteopathic question bank (Combank, Comquest, etc.). My school had given us subscriptions to Combank for Level 1 and Level 2 so I decided to continue the tradition and enroll in the Level 3 question bank.

I started doing Combank questions about a month after I started UWorld and I was immediately frustrated. In my opinion juggling an osteopathic question bank and UWorld is a double edged sword. I felt that UWorld questions were more difficult and complex, but their answering and reasoning was more concise. If I knew the pathophysiology I would be able to work my way through a question and reason my way to a correct answer. If I selected the wrong answer, I felt that their explanations for why each answer was correct/not correct really solidified the concepts I was attempting to learn. Unfortunately my experience with Combank was quite the opposite. I think a lot of Combank questions force the user to “guess what [they] are thinking” as their answers often seem to be based on implied knowledge. In reviewing my completed tests I often found that the explanations did not assist me in learning. For instance if the question stem focused on a vague description of an infection and then asked what a side effect of the antibiotic of choice would be, if you selected the wrong answer it would state that this is not a side effect of the correct antibiotic instead of explaining why the antibiotic you chose was not the correct choice. However, despite my frustrations with the format of questions in Combank, I do think it is most representative of the types of questions that are on Level 3. In addition, due to the high percentage of questions that test your OMT knowledge I think reviewing one osteopathic question bank is a must.


If you are an MD preparing for Step 3, UWorld is a necessity! UWorld’s questions and explanations are hands down the most thorough and accurate resource for learning the subject matter that will be presented on Step 3/Level 3.

However for a DO preparing for Level 3, UWorld may not be the best study method. I never thought there would be a time that I did not recommend UWorld, but alas this is it! I was most nervous about the CDM portion of Level 3. As this was a new feature I didn’t have any insight as to how this is structured or how to prepare for this section. I assumed that the CDM portion of Level 3 would be similarly formatted to the CCS portion of Step 3… boy was I wrong.

The best way I can describe the format for the 51 interactive CCS cases on UWorld (and presumably the CCS cases in USMLE Step 3) is like a “choose your own adventure” type story. You are presented with a patient’s chief complaint and HPI and you are essentially given a blank canvas as to how to manage the patient. You decide what to examine, what labs to choose, which imaging to be done and how often you want to see the patient. If the patient is critically ill you have to be sure to put in *stat* orders for labs and imaging before you click the boxes to do a physical exam and you have to order labs & imaging in a sequence that makes sense (RUQ ultrasound before jumping to a HIDA). You are required to put in orders for things that are usually done for you without much though such as when vitals are read, to obtain peripheral IV access, to put a patient in a C-collar etc. Each interaction is timed (between 10-20 minutes) and you have the ability to advance the imaginary clock as desired, whether be in an hour to get the results of an x-ray to in a couple days to see if you’re patient’s symptoms have resolved. If you input the correct lab/imaging/consult etc, when you advance the clock you will get a confirmation of your diagnosis, or resolution of the problem you have been treating and the case will advance to the final two minutes of the real time interaction for you to finish inputting orders (for follow up, outpatient medications, etc.) and to give your final diagnosis.

I spent days leading up to my Level 3 exam just practicing the interactive cases on UWorld. I reviewed the practice cases and made flashcards for the labs and procedures I didn’t think I’d remember come test day. I walk into testing Day 2 of Level 3 and immediately realized I had way over prepared for the CDM portion of the exam.

The CDM portion of Level 3 in theory is similar to CCS of Step 3. It is testing your ability to manage a patient and make clinical decisions, however it is not as open to interpretation as CCS. The format for CDM, as mentioned above is multiple choice and short answer questions. If I were to select labs for a patient I was given 12 different options and I had to select my top 3 choices. The short answer text boxes were answers to specific questions like a common side effect to a specific medication or which imaging study to evaluate the problem. What I liked most about the CDM cases compared to CCS is you instantly knew if you were right or wrong (After selecting the top 3 choices for labs after clicking the next button you see the results of the 3 labs you should have ordered).

In hindsight, I think I would’ve saved myself the money and not gotten an UWorld Subscription. I think 1 question bank is sufficient in preparing for Level 3, and as there is no OMT on UWorld it is an incomplete resource for DOs preparing for their boards.

Step 3 Secrets

I read this book cover to cover to prepare for Level 3 and I cannot recommend it enough! Just like the other books in the “Secrets” series, the format of this book is question and answer split up by specialty. This book covers the highest yield diseases, patient presentations, labs, imaging findings and pharmacology you may need to know. The chapters are quick and easy to read, and there are high yield charts that are good for last minute reviewing. In the front of the book are full color pictures of common dermatology complaints or imaging findings you will need to be able to recognize. Given how cheap this book and how much content it covers efficiently this book is an absolute no-brainer when preparing for your Level 3/Step 3.

Good Luck!

2 thoughts on “COMLEX Level 3 Overview

  1. Wish I’d had seen this blog beginning of intern year. Being one year in it was mind f***. Atleast for me during the test even though, I had finish all of combank prior to taking it and scored well on the QBank. They doubled down on the OMM which is totally out of my brain by now besides the Chapman’s and VSRs. I totally agree with your assessment of COMLEX vs USMLE. I’m hoping I passed but I really don’t see how you can study for this type of test versus the USMLE. The questions feel sort of an IQ test where most of them are missing retaining information and I guess we’re supposed to use our available knowledge and take the best guess. Hoping for a curve!!!!!!!!!!! Taking part 2 soon 🤯😱


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