G61.82 ICD-10-CM Code: Multifocal motor neuropathy
G61.82 maps to CMS-HCC V28 193. A source-labeled RAF reference is available. Confirm the documented diagnosis and applicable coding requirements. MEAT criteria · RAF Calculator · free HCC coding tools
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FY 2026 Apr update / Diseases of the nervous system (G00-G99) / Polyneuropathies and other disorders of the peripheral nervous system (G60-G65)
G61.82
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceMultifocal motor neuropathy
A rare autoimmune nerve disorder that affects motor nerves in multiple, separate locations, causing progressive muscle weakness and atrophy.
Buddy Insight
Multifocal motor neuropathy is a rare immune-mediated neuropathy that selectively affects motor nerves in an asymmetric distribution, leading to progressive weakness without sensory loss.
CMS-HCC V28
MappedHCC 193
Code-level coefficient reference
CMS-HCC V24
HistoricalHistorical
Not used for CY2026 payment
ACA/HHS
MappedHCC 115
Code-level coefficient reference
ESRD/PACE
MappedHCC 75
Code-level coefficient reference
RXHCC
MappedHCC 157
Code-level coefficient reference
Code Book Path
Inclusion Terms
Official- MMN
Excludes 2
Official- certain conditions originating in the perinatal period (P04-P96)Inherited from G00-G99
- certain infectious and parasitic diseases (A00-B99)Inherited from G00-G99
- complications of pregnancy, childbirth and the puerperium (O00-O9A)Inherited from G00-G99
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)Inherited from G00-G99
- endocrine, nutritional and metabolic diseases (E00-E88)Inherited from G00-G99
- injury, poisoning and certain other consequences of external causes (S00-T88)Inherited from G00-G99
- neoplasms (C00-D49)Inherited from G00-G99
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)Inherited from G00-G99
Related Codes
Includes
OfficialNo Includes notes are included in this display for G61.82. Check the code and parent instructions in the Code Book.
Excludes 1
Official- neuralgia NOS (M79.2)Inherited from G60-G65
- neuritis NOS (M79.2)Inherited from G60-G65
- peripheral neuritis in pregnancy (O26.82-)Inherited from G60-G65
- radiculitis NOS (M54.10)Inherited from G60-G65
Code First
OfficialNo Code First sequencing instructions are included in this display for G61.82. Check the code and parent instructions in the Code Book.
Use Additional
OfficialNo Use Additional Code instructions are included in this display for G61.82. Check the code and parent instructions in the Code Book.
Code Also
OfficialNo Code Also instructions are included in this display for G61.82. Check the code and parent instructions in the Code Book.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is G61.82 an HCC code?
Yes. G61.82 (Multifocal motor neuropathy) maps to HCC 193, Chronic Inflammatory Demyelinating Polyneuritis and Multifocal Motor Neuropathy under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 1.692. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.
Coder answer: G61.82 is billable and maps to V28 HCC 193, Chronic Inflammatory Demyelinating Polyneuritis and Multifocal Motor Neuropathy. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- G61.82
- Description
- Multifocal motor neuropathy
- HCC (V28)
- HCC 193 — Chronic Inflammatory Demyelinating Polyneuritis and Multifocal Motor Neuropathy
- RAF reference coefficient
- 1.692
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.
Work G61.82 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →
MEAT review for G61.82
For G61.82, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule.
- 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
Coder workflow notes
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What This Code Means
G61.82 is the ICD-10-CM diagnosis code for multifocal motor neuropathy. A rare autoimmune nerve disorder that affects motor nerves in multiple, separate locations, causing progressive muscle weakness and atrophy. G61.82 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, G61.82 maps to Chronic Inflammatory Demyelinating Polyneuritis and Multifocal Motor Neuropathy (HCC 193) with a source-labeled community, non-dual, aged reference coefficient of 1.692. No V24 mapping is shown for G61.82; use the applicable model and payment year when reviewing the V28 mapping. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.
Ensure documentation specifies multifocal involvement rather than generalized polyneuropathy. For G61.82, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. 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, source-labeled coefficient references, and MEAT documentation criteria for G61.82 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Ensure documentation specifies multifocal involvement rather than generalized polyneuropathy
- •This condition is distinct from other inflammatory polyneuropathies; verify diagnostic confirmation in records
Clinical Significance
Multifocal motor neuropathy is a rare immune-mediated neuropathy that selectively affects motor nerves in an asymmetric distribution, leading to progressive weakness without sensory loss. It requires expensive ongoing immunoglobulin therapy. Accurate coding is essential as it reflects a complex neurological condition with high treatment costs and significant disability potential.
Documentation Requirements
- ✓Asymmetric motor weakness documented in specific nerve distributions
- ✓Nerve conduction studies showing multifocal conduction block in motor nerves
- ✓Absence of significant sensory involvement (key distinguishing feature)
- ✓Anti-GM1 antibody testing results when available
- ✓Treatment with intravenous immunoglobulin or subcutaneous immunoglobulin
- ✓Provider's explicit diagnosis of multifocal motor neuropathy
Commonly Confused Codes
- •G61.81: CIDP affects both motor and sensory nerves symmetrically, while multifocal motor neuropathy is asymmetric and motor-only
- •G12.21: Amyotrophic lateral sclerosis can mimic multifocal motor neuropathy early in course; nerve conduction studies help differentiate
- •G61.0: Guillain-Barre syndrome is acute and symmetric, unlike the chronic asymmetric pattern of multifocal motor neuropathy
- •G61.89: Other inflammatory polyneuropathies is a less specific alternative that should not be used when multifocal motor neuropathy is confirmed