ICD-10-CM 2027
ICD-10 code for Louping ill encephalitis
From the official ICD-10-CM alphabetic index entry “Encephalitis (chronic) (hemorrhagic) (idiopathic) (nonepidemic) (spurious) (subacute) › louping ill”. Page updated September 29, 2026.
About coding Louping ill encephalitis
The ICD-10-CM code for Louping ill encephalitis is A84.89 (Other tick-borne viral encephalitis).
Within A84.8, choose A84.89 (Other tick-borne viral encephalitis) only when documentation doesn't support a more specific option: Powassan virus disease (A84.81).
Code first: , if applicable, transfusion related infection (T80.22-).
As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" MS-DRG of its family, unless the principal diagnosis excludes it.
Common questions about Louping ill encephalitis ICD-10 codes
What is the ICD-10 code for Louping ill encephalitis?
- A84.89 — Other tick-borne viral encephalitis.
Is A84.89 billable?
- Yes. A84.89 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A84.89 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A84.89 as a principal diagnosis.
Is A84.89 a CC or MCC?
- A84.89 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.