ICD-10 Code G51.9 – Disorder of facial nerve, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G51.9 – Disorder of facial nerve, unspecified
What it is
This code identifies a disorder affecting the facial nerve when the specific cause or type is not documented. Use it when the record confirms facial nerve involvement but does not name a more precise diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings may include facial weakness, asymmetry, drooping, or impaired facial movement on one side.
When to use this code
Use G51.9 when the clinician documents a facial nerve disorder but the note does not specify palsy, inflammation, or another defined condition. It also fits when the diagnosis is incomplete and you cannot assign a more specific code from the record.
Do not use for
Do not use this code when documentation supports a more specific facial nerve diagnosis, such as Bell palsy or another named disorder. Check documentation if the condition is clearly due to trauma, infection, or another identified cause.
Coding tip
Query for the exact facial nerve diagnosis before defaulting to G51.9.