2027 ICD-10-CM Diagnosis Code G51.31Clonic hemifacial spasm, right

ICD-10-CM Codes›G00–G99›G50-G59›G51

ICD-10-CM G51.31
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G51.31 is a billable ICD-10-CM diagnosis code for clonic hemifacial spasm, right. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 73 through 74. Coders also document this condition as clonic facial spasm. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nerve and nerve root disorders.

Code Identity

ICD-10-CM Code
G51.31
Billable Status
Yes — Valid for Submission
Code Describes
Clonic hemifacial spasm, right
Short Description
Clonic hemifacial spasm, right
Same as the full description in the CMS dataset.
Parent Code
G51.3
Clonic hemifacial spasm

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG50-G59Nerve, nerve root and plexus disorders
CategoryG51Facial nerve disorders
This CodeG51.31Clonic hemifacial spasm, right

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Clonic facial spasm
  • Clonic hemifacial spasm of right facial muscle
  • Disorder of right facial nerve
  • Hemifacial spasm
  • Hemifacial spasm of right facial nerve

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G51.31: its own notes plus those printed at G51, block G50-G59, and Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From G51 Facial nerve disorders applies to 10 codes
  • disorders of 7th cranial nerve

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Block G50-G59 Nerve, nerve root and plexus disorders applies to 106 codes
  • current traumatic nerve, nerve root and plexus disorders - see Injury, nerve by body region
  • neuralgia NOS (M79.2)
  • neuritis NOS (M79.2)
  • peripheral neuritis in pregnancy (O26.82-)
  • radiculitis NOS (M54.1-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Chapter 6 (G00-G99) Diseases of the nervous system applies to 700 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

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

Clinical InformationClinical

  • 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.

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.

Code History & ChangesHistory

Replacement G51.31 replaces the following previously assigned code(s):

  • G51.3 - Clonic hemifacial spasm
FY 2019AddedAdded to the ICD-10-CM code setEffective October 1, 2018.
FY 2020–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G51.31Overview

What is the ICD-10 code for clonic hemifacial spasm, right?

The ICD-10-CM code for clonic hemifacial spasm, right is G51.31 (sometimes written as G5131). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G51.31 (Clonic hemifacial spasm) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report clonic hemifacial spasm, right on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G51.31 group to?

When clonic hemifacial spasm, right is the principal diagnosis on an inpatient stay, it groups to MS-DRG 74, 73, with relative weights from 1.0172 to 1.5773 depending on complications. Higher weights mean higher Medicare reimbursement.

Can G51.31 be reported with M79.2?

Not as a rule. The Excludes1 note at block G50-G59, which applies to G51.31, lists "neuralgia NOS (M79.2)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).