ICD-10 Code B08.01 – Cowpox and vaccinia not from vaccine (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code B08.01 – Cowpox and vaccinia not from vaccine
What it is
B08.01 identifies a poxvirus infection due to cowpox or vaccinia when it is not related to vaccination. Use it for documented natural infection, not for routine vaccine-associated reactions.
Clinical signs
Typical findings include localized skin lesions that may become vesicular, pustular, or crusted, sometimes with surrounding inflammation. Clinical features vary; refer to documentation.
When to use this code
Use this code when the record clearly states cowpox or vaccinia infection and the source is not a vaccine exposure. It is appropriate for confirmed or provider-documented cases involving skin lesions or other manifestations attributed to these viruses. Check documentation if the note only says “poxvirus infection.”
Do not use for
Do not use B08.01 for vaccine-related adverse effects or routine post-vaccination reactions. Do not assign it when the diagnosis is unspecified or when another more specific poxvirus code is documented.
Coding tip
Confirm the provider distinguishes natural infection from vaccination-related illness before you code B08.01.