ICD-10 Code A79.81 – Rickettsiosis due to Ehrlichia sennetsu (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A79.81 – Rickettsiosis due to Ehrlichia sennetsu
What it is
A79.81 identifies rickettsiosis caused by Ehrlichia sennetsu, an infectious illness in the rickettsial group. Use it when the record specifically names this organism or diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Reported findings may include a febrile illness with nonspecific systemic symptoms, but you should code only when the provider documents this specific infection.
When to use this code
Use A79.81 when the clinician diagnoses rickettsiosis due to Ehrlichia sennetsu, or when the organism is identified as the cause of illness. This code supports confirmed or documented suspected cases if the provider records the condition. Check documentation for any additional manifestations that may need separate coding.
Do not use for
Do not use this code for other ehrlichial infections, unspecified rickettsiosis, or general febrile illness without a documented organism. If the chart does not clearly name Ehrlichia sennetsu, check documentation.
Coding tip
Code the organism-specific diagnosis only when the provider states Ehrlichia sennetsu explicitly.