ICD-10-CM 2027
ICD-10 code for Bartonella fever
From the official ICD-10-CM alphabetic index entry “Fever (inanition) (of unknown origin) (persistent) (with chills) (with rigor) › Bartonella”. Page updated September 29, 2026.
About coding Bartonella fever
The ICD-10-CM code for Bartonella fever is A44.0 (Systemic bartonellosis).
Within A44 (bartonellosis), A44.0 is specifically for systemic bartonellosis. Related codes cover cutaneous and mucocutaneous bartonellosis (A44.1), other forms of bartonellosis (A44.8) and unspecified (A44.9).
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.
Common questions about Bartonella fever ICD-10 codes
What is the ICD-10 code for Bartonella fever?
- A44.0 — Systemic bartonellosis.
Is A44.0 billable?
- Yes. A44.0 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A44.0 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A44.0 as a principal diagnosis.
Is A44.0 a CC or MCC?
- A44.0 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.