Hello Courtney,
I also agree with what Elizabeth stated, to remember keywords. Can anyone remember all 21 chapter specific guidelines, ummmmm don't think so, but can you remember keywords that will guide you to a specific section, yes you can!
I am a coding instructor at a local college, I always have my students to practice and remember as much as they can from their ICD-10-CM book, reason is because when you take the exam, is time-based so the more you know the less time you spent thinking about it.
For instance, I have them try to remember what each chapter is, chapter 1 is for infections, chapter 9 circulatory, chapter 18 signs and symptoms, what kind of codes do you see in chapter 1? A-B codes, and 9? I codes and 18? R codes. So Yes it might seem like a lot that I request but then I put my reasoning and experience behind it. As you start coding on the outside world, you start memorizing and learning more than what you see at school, in online course, practice courses etc., but when it comes to the exam, if you have a question that is asking you to code only the signs or symptoms, and lets say 2 answers have an actual "confirmed" condition code, meaning its coming from another chapter other than 18, and the other 2 answers will have symptom codes, then process of elimination comes in by knowing your codes and applying your guidelines.
if the answers look like this
A. J18.9
B. J18.9. J44.9
C. R06.02
D. R06.02, R05
if the case says patient had possible pneumonia and COPD (which is your codes J18.9 and J44.9) but they couldn't confirm it because they need more testing, then if you remember your guidelines, we don't code possible condition so we would code the symptoms the patient came in with. So if patient came in with cough (R05) and shortness of breath (R06.02) then you would be able to eliminate right away A and B.
Again, the more you know, the better it will be. get to know your books, both ICD-10 and CPT and review your guidelines as much as you can.
Hope this helps!