ICD-10-CM 2027
ICD-10 code for bartonellosis
From the official ICD-10-CM alphabetic index entry “Bartonellosis”. Page updated September 29, 2026.
About coding bartonellosis
The ICD-10-CM code for bartonellosis is A44.9 (Bartonellosis, unspecified). The official index lists 4 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on A44.9.
Within A44, choose A44.9 (unspecified) only when documentation doesn't support a more specific option: systemic bartonellosis (A44.0), cutaneous and mucocutaneous bartonellosis (A44.1) and other forms of bartonellosis (A44.8).
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.
More specific bartonellosis codes (official index)
Common questions about bartonellosis ICD-10 codes
What is the ICD-10 code for bartonellosis?
- A44.9 — Bartonellosis, unspecified. More specific codes apply when the documentation supports them: A44.1, A44.1, A44.8, A44.0.
What is the ICD-10 code for cutaneous bartonellosis?
- A44.1 — Cutaneous and mucocutaneous bartonellosis.
What is the ICD-10 code for mucocutaneous bartonellosis?
- A44.1 — Cutaneous and mucocutaneous bartonellosis.
What is the ICD-10 code for systemic bartonellosis?
- A44.0 — Systemic bartonellosis.
Is A44.9 billable?
- Yes. A44.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can A44.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict A44.9 as a principal diagnosis.
Is A44.9 a CC or MCC?
- A44.9 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.