ICD-10 Code A28.9 – Zoonotic bacterial disease, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A28.9 – Zoonotic bacterial disease, unspecified
What it is
This code identifies a bacterial infection that spreads from animals to humans, but the specific organism is not named in the record. Use it when documentation confirms a zoonotic bacterial disease without a more precise diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Commonly, records describe an infection linked to animal exposure, but the exact presentation depends on the organism involved and the affected body system.
When to use this code
Use A28.9 when the provider documents a zoonotic bacterial infection and does not specify the causative agent. It also fits when the chart confirms an animal-to-human bacterial disease, but the final organism identification is unavailable. Check documentation if a more specific code is supported.
Do not use for
Do not use this code for nonbacterial zoonotic infections or when a specific zoonotic bacterial diagnosis is documented. If the record names the organism or a different infectious category, code that condition instead.
Coding tip
Query for the organism and exposure source before assigning A28.9, because a more specific code may be available.