EM Coding Alert

Question: Encounter notes indicate that the neurosurgeon performed critical care on a 5-year-old patient with necrotizing hemorrhagic encephalopathy. What is the correct ICD-10-CM code for this condition?

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Answer: The correct code will depend on a few more pieces of information. According to Codify, necrotizing hemorrhagic encephalopathy “is a rare brain disease characterized by swelling, hemorrhage (bleeding), and necrosis (cell/tissue death) that primarily affects children following a gastrointestinal or respiratory viral infection.” The question is how and when the condition manifested itself.

If the encephalopathy is acute, your best choice is G04.30 (Acute necrotizing hemorrhagic encephalopathy, unspecified).

If the encephalopathy appeared after a recent infection, you should opt for G04.31 (Postinfectious acute necrotizing hemorrhagic encephalopathy). The infection could be from any viral illness, such as COVID or influenza, and the encephalopathy could take days to weeks to appear.

If the condition appeared after a recent vaccine administration with no signs of infection, report G04.32 (Postimmunization acute necrotizing hemorrhagic encephalopathy). If you report G04.32, be sure to also “Use additional code to identify the vaccine (T50.A- [Poisoning by, adverse effect of and underdosing of bacterial vaccines], T50.B- [Poisoning by, adverse effect of and underdosing of viral vaccines], T50.Z- [Poisoning by, adverse effect of and underdosing of other vaccines and biological substances]),” per ICD-10-CM. A postimmunization encephalopathy usually occurs more quickly than a postinfectious encephalopathy, though it can take up to two weeks to manifest.

If none of the above options makes sense, you should settle on G04.39 (Other acute necrotizing hemorrhagic encephalopathy). When reporting G04.39, ICD-10-CM instructs you to “Code also underlying etiology, if applicable.”

Chris Boucher, MS, CPC, Senior Development Editor, AAPC