ICD-10 Code J01.9 – Acute sinusitis, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code J01.9 – Acute sinusitis, unspecified
What it is
J01.9 identifies an acute sinus infection when the affected sinus is not specified in the documentation. Use it for a short-term inflammatory or infectious process involving the paranasal sinuses.
Clinical signs
Common findings include nasal congestion, facial pressure or pain, purulent nasal drainage, and reduced sense of smell. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents acute sinusitis but does not name the sinus involved, such as maxillary, frontal, or ethmoidal. It also fits cases where the chart supports acute sinusitis, but the specific site is not recorded. Do not guess a more specific code.
Do not use for
Do not use J01.9 for chronic sinusitis or for allergic rhinitis without sinus infection. If the record identifies a specific sinus or another cause, code that documented condition instead.
Coding tip
Check the note for the sinus location and acuity before assigning J01.9.