Facial nerve disorders (G51) ICD-10-CM
The G51 code range covers facial nerve disorders with 12 ICD-10-CM diagnosis codes. 10 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
- disorders of 7th cranial nerve
Codes in the G51 Range 12 codes · 10 billable
- G51 Facial nerve disordersNon-billable
- G51.0 Bell's palsy
- G51.1 Geniculate ganglionitis
- G51.2 Melkersson's syndrome
- G51.3 Clonic hemifacial spasmNon-billable
- G51.31 Clonic hemifacial spasm, right
- G51.32 Clonic hemifacial spasm, left
- G51.33 Clonic hemifacial spasm, bilateral
- G51.39 Clonic hemifacial spasm, unspecified
- G51.4 Facial myokymia
- G51.8 Other disorders of facial nerve
- G51.9 Disorder of facial nerve, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the G51 range.
Bell Palsy
A syndrome characterized by the acute onset of unilateral FACIAL PARALYSIS which progresses over a 2-5 day period. Weakness of the orbicularis oculi muscle and resulting incomplete eye closure may be associated with corneal injury. Pain behind the ear often precedes the onset of paralysis. This condition may be associated with HERPESVIRUS 1, HUMAN infection of the facial nerve. (Adams et al., Principles of Neurology, 6th ed, p1376)
Facial Hemiatrophy
A syndrome characterized by slowly progressive unilateral atrophy of facial subcutaneous fat, muscle tissue, skin, cartilage, and bone. The condition typically progresses over a period of 2-10 years and then stabilizes.
Facial Nerve Diseases
Diseases of the facial nerve or nuclei. Pontine disorders may affect the facial nuclei or nerve fascicle. The nerve may be involved intracranially, along its course through the petrous portion of the temporal bone, or along its extracranial course. Clinical manifestations include facial muscle weakness, loss of taste from the anterior tongue, hyperacusis, and decreased lacrimation.
Melkersson-Rosenthal Syndrome
An idiopathic syndrome characterized by one or more of the following; recurrent orofacial swelling, relapsing facial paralysis, and fissured tongue (lingua plicata). The onset is usually in childhood and relapses are common. Cheilitis granulomatosa is a monosymptomatic variant of this condition. (Dermatol Clin 1996 Apr;14(2):371-9; Magalini & Magalini, Dictionary of Medical Syndromes, 4th ed, p531)
Myokymia
Successive and rapid contractions of motor units associated with chronic nerve injury. The discharges arise from the peripheral aspects of regenerating nerves, and clinically impart a nearly continuous undulation of the body surface overlying the muscle. (Adams et al., Principles of Neurology, 6th ed, p1491)
About the G51 Code Range
Facial nerve disorders may involve facial muscle weakness, loss of taste from the front of the tongue, heightened sensitivity to sound, or fewer tears.
Within G51, subdivisions identify Bell's palsy, geniculate ganglionitis, Melkersson's syndrome, clonic hemifacial spasm, and facial myokymia. Clonic hemifacial spasm is divided into right, left, bilateral, and unspecified codes. The category also has codes for other and unspecified facial nerve disorders.
Questions About This Page
How many billable codes are in the G51 range?
Of the 12 codes in this range, 10 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the G51 range classify?
The range classifies facial nerve disorders. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
