ICD-10 Code A41.9 – Sepsis, unspecified organism (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code A41.9 – Sepsis, unspecified organism
What it is
A41.9 identifies sepsis when the organism causing the infection is not documented. Use it for a systemic response to infection with an unspecified source or pathogen.
Clinical signs
Clinical features vary; refer to documentation. Typical records describe suspected or confirmed infection with systemic illness, such as altered mental status, fever, or organ dysfunction, but the organism is not named.
When to use this code
Use A41.9 when the provider documents sepsis but does not identify the infecting organism. It also fits cases where the chart confirms sepsis and no more specific sepsis code is supported. If documentation later names the organism, code the more specific option instead.
Do not use for
Do not use this code for localized infection without sepsis. Also avoid it when the organism is documented and a more specific sepsis code is available.
Coding tip
Check the full record for the causative organism before defaulting to A41.9.