Check Excludes Notes to Avoid a Denial
Question: I've been getting a handful of denials from Humana about ICD-10-CM codes being inappropriately billed together. I assume it’s due to the codes not being mutually exclusive. However, N18.32, E83.52, N25.81, and E55.9 are all very different diagnosis codes. This is just an example of one patient we have, but there have been a few different ones with different diagnoses. How can I figure out why this is being denied? Utah Subscriber Answer: You need to check the Excludes notes for every applicable diagnosis code on your claim. You mentioned ICD-10-CM codes N18.32 (Chronic kidney disease, stage 3b), E83.52 (Hypercalcemia), N25.81 (Secondary hyperparathyroidism of renal origin), and E55.9 (Vitamin D deficiency, unspecified). For example, hyperparathyroidism is known to cause high blood calcium levels, which is why you wouldn't typically bill this with E83.52. Pay attention to E83.5 (Disorders of calcium metabolism), as there is an Excludes1 note with most of the codes for hyperparathyroidism and secondary hyperparathyroidism listed. When you encounter a denial due to a diagnosis conflict, your initial step should be to review the Excludes notes. This is typically a reliable method to ascertain if two diagnosis codes might be viewed as mutually exclusive. In this case, they are. Lindsey Bush, BA, MA, CPC, Development Editor, AAPC 
