G61.89
BillableOther inflammatory polyneuropathies
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G61.89 an HCC code?
Yes. G61.89 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 G61.89
For G61.89to 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 G61.89 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G61.89 is the ICD-10-CM diagnosis code for other inflammatory polyneuropathies. Inflammation of multiple nerves due to causes other than those specifically classified, resulting in weakness, numbness, or pain in affected areas. G61.89 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, G61.89 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.
Use this code only after excluding more specific inflammatory polyneuropathy codes (G61.0-G61.82). Because G61.89 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 G61.89 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
Clinical Significance
Other inflammatory polyneuropathies captures inflammatory nerve conditions that do not fit into specifically classified categories. While this is a residual code, it still represents significant neurological disease requiring immunomodulatory treatment and ongoing management. Proper capture ensures these patients' complexity is reflected in risk adjustment.
Documentation Requirements
- ✓Clinical evidence of inflammatory polyneuropathy: weakness, sensory changes, pain
- ✓Nerve conduction study or electromyography findings consistent with inflammatory process
- ✓Documentation that the condition does not meet criteria for Guillain-Barre syndrome, CIDP, or multifocal motor neuropathy
- ✓Identification of the specific inflammatory etiology when known
- ✓Current treatment plan and response to therapy
- ✓Provider's explicit diagnosis of inflammatory polyneuropathy with specification that it is not Guillain-Barre syndrome, CIDP, or multifocal motor neuropathy
Commonly Confused Codes
- •G61.0 — Guillain-Barre syndrome should be used when the presentation is acute ascending paralysis with specific diagnostic criteria met
- •G61.81 — CIDP should be used when the chronic demyelinating pattern is confirmed
- •G61.82 — Multifocal motor neuropathy should be used when motor-only asymmetric involvement is confirmed
- •G61.9 — Inflammatory polyneuropathy, unspecified is even less specific; use G61.89 when the provider specifies an inflammatory type not elsewhere classified