G63
BillablePolyneuropathy in diseases classified elsewhere
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G63 an HCC code?
Yes. G63 maps to Myasthenia Gravis/Myoneural Conditions and Guillain-Barre Syndrome under the V24 model but is not retained in V28.
HCC Category Mapping
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 G63
For G63to 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 G63 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G63 is the ICD-10-CM diagnosis code for polyneuropathy in diseases classified elsewhere. Nerve damage affecting multiple nerves that occurs as a secondary condition in patients with other classified diseases such as diabetes, infections, or metabolic disorders. G63 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).
Under the older CMS-HCC V24 model, G63 maps to Myasthenia Gravis/Myoneural Conditions and Guillain-Barre Syndrome (HCC 75) with a community, non-dual, aged base RAF weight of 0.425. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition.
This code requires a secondary diagnosis code for the underlying disease causing the polyneuropathy. Because G63 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for G63 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This code requires a secondary diagnosis code for the underlying disease causing the polyneuropathy
- •Always code the primary disease first, then use G63 to indicate polyneuropathy as a manifestation
Clinical Significance
Polyneuropathy in diseases classified elsewhere is a manifestation code that indicates nerve damage secondary to another systemic disease, most commonly diabetes, infections, or connective tissue disorders. It adds important clinical context showing that the underlying disease has produced neurological complications, reflecting greater disease severity and complexity.
Documentation Requirements
- ✓The underlying causative disease must be documented and coded first (etiology code sequenced before G63)
- ✓Clinical evidence of polyneuropathy: symptoms, exam findings, electrodiagnostic studies
- ✓Provider's explicit statement linking the polyneuropathy to the underlying disease
- ✓Functional impact of the polyneuropathy on the patient
- ✓Current treatment and management plan for both the underlying disease and the neuropathy
Excludes 1 — Do NOT code together
- polyneuropathy (in):
- diabetes mellitus (E08-E13 with .42)
- diphtheria (A36.83)
- infectious mononucleosis complicated by polyneuropathy (B27.0-B27.9 with fifth character 1)
- Lyme disease (A69.22)
- mumps (B26.84)
- postherpetic (B02.23)
- rheumatoid arthritis (M05.5-)
- scleroderma (M34.83)
- systemic lupus erythematosus (M32.19)
Code First
Commonly Confused Codes
- •E11.42 — Type 2 diabetes mellitus with diabetic polyneuropathy is a combination code that does not require G63 as an additional code
- •G62.9 — Polyneuropathy, unspecified is for polyneuropathy without a known underlying classified disease
- •G61.89 — Other inflammatory polyneuropathies is for primary inflammatory neuropathies, not neuropathies secondary to other diseases
- •G63 is a manifestation code — do NOT use as a standalone code; always pair with the underlying etiology