2027 ICD-10-CM Diagnosis Code G50.9Disorder of trigeminal nerve, unspecified
ICD-10-CM Codes›G00–G99›G50-G59›G50
- Billable — Valid for Submission
- Not Chronic
G50.9 is a billable ICD-10-CM diagnosis code for disorder of trigeminal nerve, unspecified. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Nerve and nerve root disorders.
G50.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 168 for payment year 2027.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
G50.9 does not risk-adjust for Medicare Advantage under the CMS-HCC V28 model, but it maps to payment categories in the other CMS models shown below.
Source: CMS Payment Year 2027 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Abnormal innervation syndrome
- Dermatosis secondary to peripheral nerve disorder
- Disorder of left trigeminal nerve
- Disorder of right trigeminal nerve
- Fifth cranial nerve abnormal
- Fifth cranial nerve finding
- Idiopathic trigeminal neuropathy
- Inverse Marcus-Gunn phenomenon
- Jaw-winking syndrome
- Neurotrophic damage to skin
- Ophthalmic nerve disorder
- Paratrigeminal syndrome
- Second division of fifth cranial nerve disorder
- Skin damage resulting from acquired nerve disorder
- Trigeminal nerve disorder
- Trigeminal nerve sensory disorder
- Trigeminal trophic syndrome
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to G50.9: its own notes plus those printed at G50, 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.
- disorders of 5th cranial nerve
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
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.
- 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.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disorder (of) See Also: Disease;
fifth G50.9
trigeminal nerve G50.9
Paralysis, paralytic (complete) (incomplete) G83.9
nerve See Also: Disorder, nerve;
trigeminal G50.9
paratrigeminal G50.9
trigeminal nerve G50.9
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Peripheral Nerve Disorders
Nerves are like wires that carry messages back and forth between your brain and your body. Your peripheral nerves branch off from your brain and spinal cord and connect to all parts of your body, including your muscles and organs.
The full article covers:
- What are peripheral nerves?
- What are peripheral nerve disorders?
- What causes peripheral nerve disorders?
- What are the symptoms of peripheral nerve disorders?
- How are peripheral nerve disorders diagnosed?
- What are the treatments for peripheral nerve disorders?
- Can peripheral nerve disorders be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert G50.9 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About G50.9Overview
What is the ICD-10 code for disorder of trigeminal nerve, unspecified?
The ICD-10-CM code for disorder of trigeminal nerve, unspecified is G50.9 (sometimes written as G509). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is G50.9 (Disorders of trigeminal nerve) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report disorder of trigeminal nerve, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does G50.9 group to?
When disorder of trigeminal nerve, unspecified 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 G50.9 be reported with M79.2?
Not as a rule. The Excludes1 note at block G50-G59, which applies to G50.9, 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).
What is the ICD-9 equivalent of G50.9?
Under the General Equivalence Mappings, disorder of trigeminal nerve, unspecified converts to ICD-9-CM 350.9 (trigeminal nerve dis NOS). The mapping is a direct match.
Does G50.9 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage: G50.9 maps to no category in the CMS-HCC V28 model. It still risk-adjusts in the RxHCC Part D (V08) category 168 (Trigeminal and Postherpetic Neuralgia).
