Many companies would like to you take an exam to determine your coding skills especially entry-level positions. If you understand coding guideline basics, then you are fine. You should know how to locate the guidelines for ICD-10-CM and CPT. That is pretty standard. Some people who only exam prep may miss the fundamentals, that could be a reason they can't perform on those exams.
Hi! AMCI has a comprehensive 4-part series on Evaluation and Management that you may find helpful. You can find the playlist here: ru-vid.com/group/PLaKD1ZIZH2LuiopBntH7tMof9sdWMUNaH&feature=shared It covers Introduction to Evaluation and Management, Hospitals and Observation Visits, Prolonged Services, and more!