ICD-10 Code A79.9 – Rickettsiosis, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A79.9 – Rickettsiosis, unspecified
What it is
A79.9 identifies rickettsial infection when the specific type is not documented. Use it for a nonspecific diagnosis of rickettsiosis, not for a confirmed organism or named syndrome.
Clinical signs
Clinical features vary; refer to documentation. Rickettsial illnesses commonly present with fever, headache, rash, or a history of arthropod exposure, but the exact pattern depends on the infection.
When to use this code
Use this code when the provider documents rickettsiosis but does not identify the species or subtype. It also fits cases where the record supports a rickettsial infection, yet the available documentation remains nonspecific. If a more specific diagnosis is later confirmed, code that condition instead.
Do not use for
Do not use A79.9 when the chart names a specific rickettsial disease, such as a defined spotted fever or typhus diagnosis. Check documentation if the record only mentions suspected exposure without confirmed infection.
Coding tip
Query for the exact rickettsial organism or syndrome before assigning A79.9, because a more specific code may be available.