B33.1 Ross River disease

Billable ICD-10-CM code, FY2026. Acts as a Complication or Comorbidity (CC) as a secondary diagnosis.

Applicable to

• Epidemic polyarthritis and exanthema
• Ross River fever

MS-DRG index

Defines the logic of DRG(s) 865-866 in MDC 18.

Approximate ICD-9-CM (GEMs)

• 066.3 Other mosquito-borne fever (approximate)

Code annotations containing back-references to B33.1

Back-references to B33.1

• Type 1 Excludes: A92 Other mosquito-borne viral fevers ("Ross River disease (B33.1)")

Back-references to B33

• Code First: H67 Otitis media in diseases classified elsewhere ("viral disease NEC (B00-B34)")

Diagnosis Index entries for B33.1

• Disease, diseased › Ross River
• Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor) › Ross River
• Polyarthritis, polyarthropathy › epidemic (Australian) (with exanthema)
• Ross River disease or fever

Nearby codes

• B33 Other viral diseases, not elsewhere classified
• B33.0 Epidemic myalgia
• B33.1 Ross River disease (this code)
• B33.2 Viral carditis
• B33.20 Viral carditis, unspecified
• B33.21 Viral endocarditis
• B33.22 Viral myocarditis
• B33.23 Viral pericarditis