How do you ask a question when you don't know what you need to ask? How do you ask for help if you don't know what exactly you're missing or overlooking, and you can't point to exactly what it is that you're not understanding, but you are certain that you're missing something?
Start by explaining what you do understand, so that your instructor knows what they don't need to point out or can spot if you've misunderstood something they need to explain further.
It's okay to start with something that seems incredibly obvious! That can be as simple as, "I know this is an outpatient coding question, but I don't see anything that looks like a procedure to code. Are there any procedures in this question?"
Your question can also be detailed, explaining what information you pulled from the documentation to code, what you actually looked up (in the code book, in the guidelines, and as additional research), what you added or removed in the final list based on what you found in the earlier step, and what your final answers are. Follow that with a request for your instructor to check your thought and coding process over. In that process, you may even find you can point to the part you are uncertain about, but it's okay if you can't.
Andrews instructors will not answer whether your codes are correct before an exam has been graded, but they are happy to help guide you to something you may be missing or overthinking if you send them your steps! Better to send them too much information than too little. It may help to dictate to yourself each step you take when you're typing everything out to make sure you don't miss some little thing you did, or to ask a family member or friend to try to follow your steps the first time or two you do this to see if you've left anything out.
If all else fails, it's okay to simply state that you're stuck on question X and ask for help with where to start! The instructor may send back some questions to prompt you for the information they need, so that they can better identify what you need help in particular with.