Question: A patient presents to the ED with chest pain. The patient receives a complex cardiac workup to identify and treat or rule out a life-threatening cardiac event. By the end of the encounter, the final diagnosis was indigestion. Would this service be severe enough to warrant a 99285? Montana Subscriber Answer: Yes. There is a certain complexity associated with emergency department (ED) coding. Sometimes coders who have limited ED coding experience may find it difficult to understand the complexity of identifying the appropriate treatment or diagnosis in the ED, according to Todd Thomas, CPC, CCS-P, president for ERcoder, Inc. in Edmond, Oklahoma. "Inexperienced coders and auditors will often assign an E/M code based on their interpretation of the severity of the final diagnosis when it should be assigned based on the severity of the presenting problem," Thomas says. So in your case, a code such as 99285 (Emergency department visit for the evaluation and management of a patient, which requires these 3 key components ...) would be appropriate. According to Thomas, you should not base the code on the final diagnosis, but rather the presenting problem and the work you did to arrive to the final diagnosis. Medical necessity should be the over-arching criteria. If you needed to perform all of those tests and you used complex decision making to come to the conclusion that the patient had indigestion, that should not negate the work that went into getting to the final diagnosis.