ICD-10 Code A44 – Bartonellosis (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A44 – Bartonellosis
What it is
A44 identifies bartonellosis, an infection caused by Bartonella species. Use it when the record documents this specific diagnosis, not just a possible exposure or nonspecific febrile illness.
Clinical signs
Clinical features vary; refer to documentation. Bartonellosis may present with fever, lymph node enlargement, or other organ involvement depending on the Bartonella species and syndrome.
When to use this code
Use A44 when the clinician documents bartonellosis, cat-scratch disease, trench fever, or another Bartonella infection classified here. It also fits confirmed infection with supporting clinical assessment, even if the exact species is not stated.
Do not guess this code from animal exposure alone. If the note only says suspected infection, fever of unknown origin, or abnormal serology without a diagnosis, check documentation.
Do not use for
Do not use A44 for mere Bartonella exposure, carrier status, or nonspecific lymphadenitis without an infection diagnosis. Check documentation if the chart instead names a different infectious cause.
Coding tip
Match the code to the documented Bartonella syndrome and avoid coding from test results alone.