G61.81
BillableChronic inflammatory demyelinating polyneuritis
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is G61.81 an HCC code?
Yes. G61.81 maps to Chronic Inflammatory Demyelinating Polyneuritis under the CMS-HCC V28 risk adjustment model (and Myasthenia Gravis/Myoneural Conditions and Guillain-Barre Syndrome under V24).
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 G61.81
For G61.81to 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 G61.81 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
G61.81 is the ICD-10-CM diagnosis code for chronic inflammatory demyelinating polyneuritis. A long-term autoimmune condition where the protective covering of nerves is progressively damaged, causing weakness and impaired nerve function that worsens over time. G61.81 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 CMS-HCC V28 risk adjustment model, G61.81 maps to Chronic Inflammatory Demyelinating Polyneuritis (HCC 193) with a community, non-dual, aged base RAF weight of 0.000. Under the older CMS-HCC V24 model, G61.81 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 is a chronic condition; document the duration and progression of symptoms in the medical record. Because G61.81 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 G61.81 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a chronic condition; document the duration and progression of symptoms in the medical record
- •Distinguish from acute Guillain-Barré syndrome (G61.0) by the chronic, progressive nature of this condition
Clinical Significance
Chronic inflammatory demyelinating polyneuritis (CIDP) is a progressive autoimmune condition requiring ongoing immunomodulatory therapy such as intravenous immunoglobulin or plasmapheresis, often at considerable cost. It significantly impacts patient functional status and quality of life. Accurate coding captures the chronic care burden and recurring treatment costs associated with this condition.
Documentation Requirements
- ✓Chronic course documented: symptoms persisting beyond 8 weeks (distinguishes from Guillain-Barre syndrome)
- ✓Nerve conduction studies showing demyelinating pattern
- ✓Progressive or relapsing-remitting pattern of weakness
- ✓Current treatment regimen: intravenous immunoglobulin, corticosteroids, or plasmapheresis
- ✓Functional impairment assessment: mobility, activities of daily living
- ✓Provider's explicit diagnosis of CIDP
Commonly Confused Codes
- •G61.0 — Guillain-Barre syndrome is acute (resolves within 8 weeks); CIDP is the chronic counterpart lasting months to years
- •G61.82 — Multifocal motor neuropathy affects only motor nerves in an asymmetric pattern, while CIDP affects both sensory and motor nerves symmetrically
- •G62.9 — Polyneuropathy, unspecified should not be used when CIDP is documented; always code to the specific diagnosis
- •G61.89 — Other inflammatory polyneuropathies is used for inflammatory neuropathies that do not meet CIDP diagnostic criteria