ICD-10 Code A79 – Other rickettsioses (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A79 – Other rickettsioses
What it is
A79 identifies rickettsial infections that do not fit a more specific ICD-10 category. Use it for documented rickettsioses when the record names a nonspecific or other type.
Clinical signs
Clinical features vary; refer to documentation. Rickettsioses commonly present as an acute febrile illness, often with headache, rash, or a history of arthropod exposure.
When to use this code
Use A79 when the provider documents “other rickettsiosis,” “rickettsial infection, unspecified type,” or another nonclassifiable rickettsial illness. It may also apply when the chart confirms rickettsiosis but does not name a more specific organism or syndrome.
Do not use for
Do not use A79 if the record identifies a more specific rickettsial diagnosis that has its own code. Check documentation if the illness is still being ruled out or if the organism is not confirmed.
Coding tip
Code the most specific rickettsial diagnosis available; if specificity is lacking, A79 is the fallback only when documentation supports a rickettsiosis.