ICD-10-CM 2027
ICD-10 code for encephalitis mumps
From the official ICD-10-CM alphabetic index entry “Mumps › encephalitis”. Page updated September 29, 2026.
About coding encephalitis mumps
The ICD-10-CM code for encephalitis mumps is B26.2 (Mumps encephalitis).
Within B26 (mumps), B26.2 is specifically for mumps encephalitis. Related codes cover orchitis (B26.0), meningitis (B26.1), pancreatitis (B26.3), with other complications (B26.8) and without complication (B26.9).
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.
In MS-DRG v44.0, it is part of the grouping logic for DRG 023 (Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis with MCC or Antineoplastic Implant or Epilepsy with Neurostimulator, relative weight 5.7444), DRG 024 (Craniotomy with Major Device Implant or Acute Complex CNS Principal Diagnosis without MCC, relative weight 3.9708), DRG 097 (Non-Bacterial Infection of Nervous System Except Viral Meningitis with MCC, relative weight 3.8226), DRG 098 (Non-Bacterial Infection of Nervous System Except Viral Meningitis with CC, relative weight 2.2706), DRG 099 (Non-Bacterial Infection of Nervous System Except Viral Meningitis without CC/MCC, relative weight 1.5256), DRG 791 (Prematurity with Major Problems, relative weight 4.1075) and 1 more, in MDC 01 (Diseases and Disorders of the Nervous System) and MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Common questions about encephalitis mumps ICD-10 codes
What is the ICD-10 code for encephalitis mumps?
- B26.2 — Mumps encephalitis.
Is B26.2 billable?
- Yes. B26.2 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can B26.2 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict B26.2 as a principal diagnosis.
Is B26.2 a CC or MCC?
- B26.2 is an MCC (major complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.