Question 1

What is ICD-10 code G64?

Accepted Answer

G64 is the ICD-10-CM diagnosis code for other disorders of peripheral nervous system. Various disorders affecting the peripheral nervous system (nerves outside the brain and spinal cord) that don't fit into other specific nerve disorder categories. G64 sits in the ICD-10-CM chapter for diseases of the nervous system (g00-g99), within the section covering polyneuropathies and other disorders of the peripheral nervous system (g60-g65).

G64 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.

This is a residual category; ensure more specific codes are not available before using G64.

Question 2

Is G64 an HCC code?

Accepted Answer

No. G64 is a billable ICD-10-CM code but does not map to any payment HCC category under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can still be reported on Medicare Advantage encounter data submissions, but it does not contribute to the beneficiary's Risk Adjustment Factor (RAF) score and therefore does not affect the risk-adjusted capitation payment to the plan. V28 reached 100% phase-in for payment year 2026.

Question 3

Is G64 billable?

Accepted Answer

Yes. G64 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. G64 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.

Question 4

What is the V28 vs V24 difference for G64?

Accepted Answer

G64 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 G64 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.

Question 5

What should coders know when reporting G64?

Accepted Answer

This is a residual category; ensure more specific codes are not available before using G64 Document the specific peripheral nerve condition in clinical notes for clarity

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G64

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G64 ICD-10-CM Code: Other disorders of peripheral nervous system

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G64

Is G64 an HCC code?

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