ICD-10 Code A49.9 – Bacterial infection, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A49.9 – Bacterial infection, unspecified
What it is
A49.9 identifies a bacterial infection when the organism or site is not specified in the record. Use it for a documented bacterial infection that lacks enough detail for a more exact code.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include signs of infection such as fever, localized inflammation, or positive culture evidence, but the record must support a bacterial cause.
When to use this code
Use A49.9 when the clinician documents a bacterial infection but does not name the organism or provide a more specific diagnosis. It also fits cases where the note confirms infection, but the source remains unclear. If the site or organism is later identified, code the more specific option instead.
Do not use for
Do not use this code for viral, fungal, or parasitic infections, or when a more specific bacterial code is documented. Check documentation if the infection is described by body site or organism.
Coding tip
Before assigning A49.9, look for a documented organism, infection site, or related condition that allows a more precise code.