What is ICD-10 code G50.8?

G50.8 is the ICD-10-CM diagnosis code for Other disorders of trigeminal nerve. Other disorders affecting the trigeminal nerve not classified elsewhere, such as nerve compression, inflammation, or dysfunction. It belongs to the ICD-10-CM chapter for diseases of the nervous system (g00-g99). G50.8 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. G50.8 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. G50.8 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. G50.8 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

What is the V28 vs V24 difference for G50.8?

G50.8 does not map to a payment HCC under either the CMS-HCC V28 risk adjustment model or the older V24 model. V28 reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Because neither model rewards G50.8 with a risk adjustment factor, it contributes zero to a Medicare Advantage beneficiary's RAF score in either version. Coders should check whether provider documentation supports a more specific child code that does map to a payment HCC.

What should coders know when reporting G50.8?

Use this code only when the trigeminal nerve disorder cannot be assigned to a more specific code (G50.0, G50.1, or G50.9) Document the specific pathology affecting the trigeminal nerve

G50.8 ICD-10 Code: Other disorders of trigeminal

ICD-10-CM Code View

HCC Buddy Code Card

Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupG50.8Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Nerve, nerve root and plexus disorders (G50-G59)

G50.8

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Other disorders of trigeminal nerve

Other disorders affecting the trigeminal nerve not classified elsewhere, such as nerve compression, inflammation, or dysfunction.

Buddy Insight

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Not risk-adjusted for this model/period.

RAF 0

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Not risk-adjusted for this model/period.

RAF 0

RXHCC

Mapped

HCC 168

Trigeminal and Postherpetic N...

RAF 0.0

Code Trumping

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Code Book Path

Official

G50Disorders of trigeminal nerve

G50.8Other disorders of trigeminal nerve

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for G50.8 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for G50.8 in this effective period.

Related Child Codes

Official

G50.0Trigeminal neuralgia

G50.1Atypical facial pain

G50.9Disorder of trigeminal nerve, unspecified

Includes

Official

disorders of 5th cranial nerve

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for G50.8 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for G50.8 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for G50.8 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for G50.8 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Specific trigeminal nerve disorder identified (neuropathy, post-traumatic injury, compression)

Documentation of which trigeminal branch(es) is affected (V1, V2, V3)

Clinical findings: sensory deficit, numbness, tingling, or weakness in trigeminal distribution

Underlying cause identified if applicable (trauma, surgery, tumor, connective tissue disease)

MEAT Support

HCC Buddy guidance

Specific trigeminal nerve disorder identified (neuropathy, post-traumatic injury, compression)

Documentation of which trigeminal branch(es) is affected (V1, V2, V3)

Clinical findings: sensory deficit, numbness, tingling, or weakness in trigeminal distribution

Underlying cause identified if applicable (trauma, surgery, tumor, connective tissue disease)

Audit Caution

HCC Buddy guidance

Using G50.8 when trigeminal neuralgia (G50.0) is the correct diagnosis — neuralgia has its own code

Coding 'other' without documenting what the specific disorder is — 'other' requires an identified condition

Defaulting to unspecified (G50.9) when enough detail exists to code as G50.0, G50.1, or G50.8

Not capturing the underlying cause of trigeminal neuropathy when one is identified

Common Mistakes

HCC Buddy guidance

G50.0 (Trigeminal neuralgia) — paroxysmal pain syndrome; G50.8 is for other identified pathology

G50.1 (Atypical facial pain) — continuous poorly localized pain; different from specific nerve pathology

G50.9 (Disorder of trigeminal nerve, unspecified) — use G50.8 when a specific disorder is identified but not neuralgia or atypical pain

S04.30-S04.39 (Injury of trigeminal nerve) — acute traumatic injury; use G50.8 for chronic post-traumatic neuropathy

Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.

Is G50.8 an HCC code?

No. G50.8 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

HCC Category Mapping

RxHCCHCC 168, Trigeminal and Postherpetic Neuralgia

0.000

RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. Actual per-patient RAF contribution depends on member segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.

MEAT Criteria for G50.8

For G50.8to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed G50.8 during that encounter, not just copy-forwarded from a problem list.

What This Code Means

G50.8 is the ICD-10-CM diagnosis code for other disorders of trigeminal nerve. Other disorders affecting the trigeminal nerve not classified elsewhere, such as nerve compression, inflammation, or dysfunction. G50.8 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering nerve, nerve root and plexus disorders (g50-g59).

G50.8 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Maps to RxHCC 168 (Disorders of Immunity, Nervous System Disorders) with a RAF weight of 0.000 in the prescription drug model. No mapping to CMS-HCC V28 or V24 payment models, so no direct impact on Medicare Advantage capitation. The RxHCC mapping captures pharmacy costs for anticonvulsants (carbamazepine, oxcarbazepine), muscle relaxants, and neuropathic pain medications. No hierarchies apply.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for G50.8 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Use this code only when the trigeminal nerve disorder cannot be assigned to a more specific code (G50.0, G50.1, or G50.9)
•Document the specific pathology affecting the trigeminal nerve

Clinical Significance

Other disorders of the trigeminal nerve encompasses specific pathologies of cranial nerve V that are not trigeminal neuralgia or atypical facial pain, such as trigeminal neuropathy, post-traumatic trigeminal nerve injury, or trigeminal nerve compression syndromes. Accurate use of this code requires documentation of a specific identified disorder rather than simply an unspecified trigeminal problem. This code is important for capturing conditions that may require neurosurgical referral or specialized nerve imaging.

Documentation Requirements

✓Specific trigeminal nerve disorder identified (neuropathy, post-traumatic injury, compression)
✓Documentation of which trigeminal branch(es) is affected (V1, V2, V3)
✓Clinical findings: sensory deficit, numbness, tingling, or weakness in trigeminal distribution
✓Underlying cause identified if applicable (trauma, surgery, tumor, connective tissue disease)
✓Neurological examination documenting trigeminal nerve function
✓Imaging results if structural cause is suspected
✓Distinction from trigeminal neuralgia (G50.0) and atypical facial pain (G50.1)

Commonly Confused Codes

•G50.0 (Trigeminal neuralgia): paroxysmal pain syndrome; G50.8 is for other identified pathology
•G50.1 (Atypical facial pain): continuous poorly localized pain; different from specific nerve pathology
•G50.9 (Disorder of trigeminal nerve, unspecified): use G50.8 when a specific disorder is identified but not neuralgia or atypical pain
•S04.30-S04.39 (Injury of trigeminal nerve): acute traumatic injury; use G50.8 for chronic post-traumatic neuropathy
•B02.22 (Postherpetic trigeminal neuralgia): has its own specific code when etiology is herpes zoster