What is ICD-10 code G61.0?

G61.0 is the ICD-10-CM diagnosis code for Guillain-Barre syndrome. An acute autoimmune condition where the body's immune system attacks nerve cells, causing rapid muscle weakness and potentially paralysis that typically develops over days to weeks. G61.0 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. G61.0 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. G61.0 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. G61.0 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.

Which HCC does G61.0 map to under V28?

G61.0 has no payable CMS-HCC V28 mapping in the final FY2026 CMS file.

What RAF reference is published for G61.0?

G61.0 has no V28 reference coefficient because the final FY2026 source verifies no payable V28 mapping.

What is the V28 vs V24 difference for G61.0?

G61.0 has verified no payable V28 mapping in the final FY2026 source. Select a historical effective period before making any V24 comparison.

What documentation supports G61.0?

This is an acute condition; ensure documentation supports the diagnosis with clinical presentation and diagnostic findings Consider sequencing this as a principal diagnosis if it is the primary reason for admission G61.0 is not a CMS-HCC V28 payment code in the verified current source, so MEAT is not the payment hook. Documentation still has to support the diagnosis if you report it.

2026 ICD-10-CM G61.0: Guillain-Barre syndrome

G61.0 is not a CMS-HCC payment code. MEAT criteria · RAF Calculator · HCC coding software

ICD-10-CM Code View

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Code lookupG61.0

Effective 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)

G61.0

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

Guillain-Barre syndrome

An acute autoimmune condition where the body's immune system attacks nerve cells, causing rapid muscle weakness and potentially paralysis that typically develops over days to weeks.

Buddy Insight

Guillain-Barre syndrome is a rapidly progressive autoimmune polyneuropathy that can lead to respiratory failure and death if untreated.

Overview Risk Models Code Book Documentation Audit Notes Edition comparison

CMS-HCC V28

N/A

—

Not risk-adjusted for this model/period.

Not mapped

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 115

HHS-HCC 115 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 75

Myasthenia Gravis/Myoneural D...

Code-level coefficient reference

RXHCC

Mapped

HCC 158

Inflammatory and Toxic Neurop...

Code-level coefficient reference

Code Book Path

Official

G61Inflammatory polyneuropathy G61.0Guillain-Barre syndrome

Inclusion Terms

Official

Acute (post-)infective polyneuritis
Miller Fisher Syndrome

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

Official

G61.1Serum neuropathy G61.8Other inflammatory polyneuropathies G61.9Inflammatory polyneuropathy, unspecified

Includes

Official

No Includes notes are included in this display for G61.0. 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

Official

No Code First sequencing instructions are included in this display for G61.0. Check the code and parent instructions in the Code Book.

Use Additional

Official

No Use Additional Code instructions are included in this display for G61.0. Check the code and parent instructions in the Code Book.

Code Also

Official

No Code Also instructions are included in this display for G61.0. Check the code and parent instructions in the Code Book.

Buddy Documentation Tip

HCC Buddy guidance

Clinical presentation: acute ascending weakness, areflexia, sensory changes

Diagnostic confirmation: nerve conduction studies/electromyography findings, cerebrospinal fluid analysis showing albuminocytologic dissociation

Temporal course: onset over days to weeks with progressive pattern

Treatment plan: intravenous immunoglobulin or plasmapheresis

MEAT Support

HCC Buddy guidance

Clinical presentation: acute ascending weakness, areflexia, sensory changes

Diagnostic confirmation: nerve conduction studies/electromyography findings, cerebrospinal fluid analysis showing albuminocytologic dissociation

Temporal course: onset over days to weeks with progressive pattern

Treatment plan: intravenous immunoglobulin or plasmapheresis

Audit Caution

HCC Buddy guidance

Coding G61.0 for a patient who is in the sequelae phase rather than the acute phase — use G65.0 for residual effects

Failing to distinguish from CIDP (G61.81) when the neuropathy has been present for more than 8 weeks

Not querying the provider when documentation is vague about whether the condition is acute Guillain-Barre syndrome versus another inflammatory polyneuropathy

Missing the opportunity to capture this high-value HCC code when the diagnosis is documented but buried in the history

Common Mistakes

HCC Buddy guidance

G61.81 — Chronic inflammatory demyelinating polyneuritis (CIDP) is the chronic form lasting >8 weeks; Guillain-Barre syndrome is acute

G61.89 — Other inflammatory polyneuropathies is a catch-all for inflammatory neuropathies that do not meet Guillain-Barre syndrome criteria

G65.0 — Sequelae of Guillain-Barre syndrome is for residual effects after the acute phase has resolved, not the active disease

G62.81 — Critical illness polyneuropathy develops in ICU patients from sepsis/critical illness, not autoimmune etiology

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 G61.0 an HCC code?

G61.0 is not in the CMS-HCC V28 or V24 community payment model. G61.0 has a separate mapping under the CMS-HCC ESRD model (HCC 75 (Myasthenia Gravis/Myoneural Disorders and Guillain-Barre Syndrome/Inflammatory and Toxic Neuropathy)) and the Part D RxHCC model (HCC 158 (Inflammatory and Toxic Neuropathy)); the applicable result needs member context. G61.0 also appears in the HHS-HCC commercial risk model (HCC 115 (HHS-HCC 115 adult, RAF varies by metal level)), which is a commercial market model rather than a Medicare Advantage payment mapping.

Code: G61.0
Description: Guillain-Barre syndrome
HCC (V28): No CMS-HCC V28 mapping
RAF reference coefficient: —
Billable: Yes
Payment year: 2026

HCC Category Mapping

ESRDHCC 75, Myasthenia Gravis/Myoneural Disorders and Guillain-Barre Syndrome/Inflammatory and Toxic Neuropathy

Not separately weighted

RxHCCHCC 158, Inflammatory and Toxic Neuropathy

Not separately weighted

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 G61.0 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT review for G61.0

For G61.0, 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

G61.0 is the ICD-10-CM diagnosis code for guillain-barre syndrome. An acute autoimmune condition where the body's immune system attacks nerve cells, causing rapid muscle weakness and potentially paralysis that typically develops over days to weeks. G61.0 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).

G61.0 has no mapping under the CMS-HCC V28 or V24 community payment models. G61.0 has a separate mapping under the CMS-HCC ESRD model (HCC 75 (Myasthenia Gravis/Myoneural Disorders and Guillain-Barre Syndrome/Inflammatory and Toxic Neuropathy)) and the Part D RxHCC model (HCC 158 (Inflammatory and Toxic Neuropathy)); the applicable result needs member context. G61.0 also appears in the HHS-HCC commercial risk model (HCC 115 (HHS-HCC 115 adult, RAF varies by metal level)), which is a commercial market model rather than a Medicare Advantage payment mapping. Do not assign V28 risk adjustment value from this page; verify the applicable model and payment year before using this code for risk adjustment.

This is an acute condition; ensure documentation supports the diagnosis with clinical presentation and diagnostic findings.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for G61.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•This is an acute condition; ensure documentation supports the diagnosis with clinical presentation and diagnostic findings
•Consider sequencing this as a principal diagnosis if it is the primary reason for admission

Clinical Significance

Guillain-Barre syndrome is a rapidly progressive autoimmune polyneuropathy that can lead to respiratory failure and death if untreated. It is critical for risk adjustment because it reflects high-acuity neurological disease requiring intensive monitoring, immunotherapy, and often prolonged rehabilitation. Accurate capture ensures appropriate resource allocation for these complex patients.

Documentation Requirements

✓Clinical presentation: acute ascending weakness, areflexia, sensory changes
✓Diagnostic confirmation: nerve conduction studies/electromyography findings, cerebrospinal fluid analysis showing albuminocytologic dissociation
✓Temporal course: onset over days to weeks with progressive pattern
✓Treatment plan: intravenous immunoglobulin or plasmapheresis
✓Functional status: respiratory function monitoring, degree of paralysis
✓Provider's explicit diagnosis of Guillain-Barre syndrome

Commonly Confused Codes

•G61.81: Chronic inflammatory demyelinating polyneuritis (CIDP) is the chronic form lasting >8 weeks; Guillain-Barre syndrome is acute
•G61.89: Other inflammatory polyneuropathies is a catch-all for inflammatory neuropathies that do not meet Guillain-Barre syndrome criteria
•G65.0: Sequelae of Guillain-Barre syndrome is for residual effects after the acute phase has resolved, not the active disease
•G62.81: Critical illness polyneuropathy develops in ICU patients from sepsis/critical illness, not autoimmune etiology