ICD-10 code for brain typhus

The ICD-10-CM code for brain typhus is A75.9 (Typhus fever, unspecified).

Within A75, choose A75.9 (unspecified) only when documentation doesn't support a more specific option: epidemic louse-borne typhus fever due to Rickettsia prowazekii (A75.0), Recrudescent typhus [Brill's disease] (A75.1), due to Rickettsia typhi (A75.2) and due to Rickettsia tsutsugamushi (A75.3).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" 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 867 (Other Infectious and Parasitic Diseases Diagnoses with MCC, relative weight 2.1859), DRG 868 (Other Infectious and Parasitic Diseases Diagnoses with CC, relative weight 1.0235) and DRG 869 (Other Infectious and Parasitic Diseases Diagnoses without CC/MCC, relative weight 0.6787), in MDC 18 (Infectious and Parasitic Diseases, Systemic or Unspecified Sites), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.