What is ICD-10 code G61.89?

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. It belongs to the ICD-10-CM chapter for diseases of the nervous system (g00-g99). G61.89 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. G61.89 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. G61.89 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. G61.89 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 G61.89?

CMS phased in the V28 risk adjustment model over payment years 2024 (33%), 2025 (67%), and 2026 (100%), replacing V24. V28 consolidates HCC categories, removes some lower-acuity conditions, and recalibrates RAF weights across the entire model. G61.89 was a payment HCC under V24 (Myasthenia Gravis/Myoneural Conditions and Guillain-Barre Syndrome) but the V28 recalibration removed it from the risk adjustment model. Both models can still appear in legacy data and in payer-specific lookback periods.

What should coders know when reporting G61.89?

Use this code only after excluding more specific inflammatory polyneuropathy codes (G61.0-G61.82) Document the underlying cause of the inflammatory polyneuropathy when identifiable Because G61.89 maps to a payment HCC, the documentation must also satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's risk adjustment score.

G61.89 ICD-10 Code: Other inflammatory

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 lookupG61.89Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Polyneuropathies and other disorders of the peripheral nervous system (G60-G65)

G61.89

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

Other inflammatory polyneuropathies

Inflammation of multiple nerves due to causes other than those specifically classified, resulting in weakness, numbness, or pain in affected areas.

Buddy Insight

Other inflammatory polyneuropathies captures inflammatory nerve conditions that do not fit into specifically classified categories.

CMS-HCC V28

Not risk-adjusted for this model/period.

RAF 0

CMS-HCC V24

Mapped

HCC 75

Myasthenia Gravis/Myoneural C...

RAF 0.425

ACA/HHS

Not risk-adjusted for this model/period.

RAF 0

ESRD/PACE

Mapped

HCC 75

Myasthenia Gravis/Myoneural C...

RAF 0.0

RXHCC

Mapped

HCC 158

Guillain-Barre Syndrome and O...

RAF 0.0

Code Trumping

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Code Book Path

Official

G61Inflammatory polyneuropathy

G61.8Other inflammatory polyneuropathies

G61.89Other inflammatory polyneuropathies

Inclusion Terms

Official

ICD-10-CM does not list inclusion terms for G61.89 in this effective period.

Excludes 2

Official

ICD-10-CM does not list Excludes 2 notes for G61.89 in this effective period.

Related Child Codes

Official

G61.81Chronic inflammatory demyelinating polyneuritis

G61.82Multifocal motor neuropathy

Includes

Official

ICD-10-CM does not list Includes notes for G61.89 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for G61.89 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for G61.89 in this effective period.

Use Additional

Official

ICD-10-CM does not list Use Additional Code instructions for G61.89 in this effective period.

Code Also

Official

ICD-10-CM does not list Code Also instructions for G61.89 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

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

MEAT Support

HCC Buddy guidance

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

Audit Caution

HCC Buddy guidance

Defaulting to this code without first attempting to classify the neuropathy into a more specific G61 category

Using this code for non-inflammatory polyneuropathies (toxic, metabolic) — those belong in the G62 category

Not querying the provider for additional specificity that could allow use of a more precise code

Confusing with G62.89 (other specified polyneuropathies) which covers non-inflammatory causes

Common Mistakes

HCC Buddy guidance

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

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 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

V24HCC 75, Myasthenia Gravis/Myoneural Conditions and Guillain-Barre Syndrome

0.425

ESRDHCC 75, Myasthenia Gravis/Myoneural Conditions and Guillain-Barre Syndrome

0.000

RxHCCHCC 158, Guillain-Barre Syndrome and Other Polyneuropathies

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 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

•Use this code only after excluding more specific inflammatory polyneuropathy codes (G61.0-G61.82)
•Document the underlying cause of the inflammatory polyneuropathy when identifiable

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