2026 ICD-10-CM Diagnosis Code G51.9Disorder of facial nerve, unspecified

ICD-10-CM Codes›G00–G99›G50-G59›G51

ICD-10-CM G51.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

G51.9 is a billable ICD-10-CM diagnosis code for disorder of facial nerve, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). Coders also document this condition as disorder of left facial nerve. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nerve and nerve root disorders.

Code Identity

ICD-10-CM Code
G51.9
Billable Status
Yes — Valid for Submission
Code Describes
Disorder of facial nerve, unspecified
Short Description
Disorder of facial nerve, unspecified
Same as the full description in the CMS dataset.
Parent Code
G51
Facial nerve disorders

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG50-G59Nerve, nerve root and plexus disorders
CategoryG51Facial nerve disorders
This CodeG51.9Disorder of facial nerve, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Disorder of left facial nerve
  • Disorder of right facial nerve
  • Facial nerve disorder
  • Facial nerve motor disorder
  • Facial nerve sensory disorder
  • Seventh cranial nerve autonomic disorder

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Disease, diseased
      • facial nerve (seventh)
    • Disorder(of)
      • nerve
        • facial
    • Lesion(s) (nontraumatic)
      • cranial nerve
        • seventh
    • Neuropathy, neuropathic
      • facial nerve

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NVS017
Nerve and nerve root disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Facial Injuries and Disorders

Face injuries and disorders can cause pain and affect how you look. In severe cases, they can affect sight, speech, breathing and your ability to swallow. Fractures (broken bones), especially in the bones of your nose, cheekbone and jaw, are common facial injuries.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert G51.9 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
351.9 Facial nerve dis NOS
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About G51.9Overview

Is G51.9 (Facial nerve disorders) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report disorder of facial nerve, unspecified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of G51.9?

Under the General Equivalence Mappings, disorder of facial nerve, unspecified converts to ICD-9-CM 351.9 (facial nerve dis NOS). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.