ICD-10 Code A22 – Anthrax (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A22 – Anthrax
What it is
A22 identifies anthrax, a serious infection caused by Bacillus anthracis. Use it when the record documents anthrax infection without needing a more specific site or complication code.
Clinical signs
Clinical features vary by exposure route and may include a skin lesion with a black eschar, fever, or severe respiratory or gastrointestinal illness. Clinical features vary; refer to documentation.
When to use this code
Use A22 when the provider documents anthrax as the confirmed diagnosis. It may appear in cutaneous, inhalational, gastrointestinal, or other documented anthrax cases when no more specific ICD-10-CM code is selected. Check documentation if the site or manifestation is unclear.
Do not use for
Do not use A22 for suspected exposure, screening, or contact without confirmed disease. Do not assign it for unrelated skin ulcers or infections unless anthrax is documented.
Coding tip
Code the most specific anthrax type supported in the note, and verify whether an additional code is needed for any documented manifestation.