ICD-10 Code A22.9 – Anthrax, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A22.9 – Anthrax, unspecified
What it is
A22.9 identifies anthrax when the record does not specify the clinical form or site. Use it for a documented anthrax infection without further detail.
Clinical signs
Clinical features vary; refer to documentation. Anthrax may present with cutaneous lesions, respiratory illness, or gastrointestinal symptoms, but this code is for unspecified disease only.
When to use this code
Use A22.9 when the provider documents anthrax and does not identify a specific type, such as cutaneous, inhalational, or gastrointestinal. It also fits when the note confirms anthrax but lacks enough detail for a more specific code.
If later documentation names the form of anthrax, you should code the more specific diagnosis instead. Check documentation for site, exposure details, and final provider wording.
Do not use for
Do not use A22.9 when the record specifies a more detailed anthrax code. Do not assign it for suspected exposure, rule-out anthrax, or unrelated skin, lung, or gastrointestinal conditions.
Coding tip
Query the provider if anthrax is documented but the type is missing, because a more specific code may be available.