What Does ICD-10 Code G62.89 Mean?
ICD-10 code G62.89 (Other Specified Polyneuropathies) is a billable, valid diagnosis code used to report polyneuropathies — conditions involving damage or dysfunction across multiple peripheral nerves — when the clinical presentation is documented with specificity but does not map to any other more precisely defined subcategory within the G62 family. It sits under ICD-10-CM Chapter 6 (Diseases of the Nervous System) and is valid for HIPAA-covered transactions for fiscal year 2026 (October 1, 2025 – September 30, 2026).
Key attributes at a glance:
- Billable/specific: Yes — valid for claims submission
- NEC designation: The code functions as a “not elsewhere classifiable” catch-all for named polyneuropathies that lack a dedicated code
- Applicable settings: Inpatient and outpatient (default assignment: Yes for both)
- MS-DRG groupings: DRG 073 (Cranial and Peripheral Nerve Disorders with MCC) and DRG 074 (without MCC)
- ICD-9 crosswalk: Approximate mapping only — no exact ICD-9 equivalent exists
What Conditions and Diagnoses Does G62.89 Cover?
G62.89 is the appropriate code when a provider has named the polyneuropathy — meaning a specific etiology or pathophysiology is documented — but the condition does not have its own dedicated ICD-10-CM code. This is the key clinical distinction that separates G62.89 from the unspecified code G62.9.
Clinical entities commonly coded to G62.89 include:
- Anoxic neuropathy (nerve damage from oxygen deprivation)
- Autoimmune peripheral motor neuropathy (not otherwise specified as CIDP or multifocal motor neuropathy with conduction block)
- Multifocal motor neuropathy (MMN) — confirmed by NCS/EMG, indexed directly to G62.89
- Paraneoplastic polyneuropathy (when documented as the diagnosis rather than coded via an underlying malignancy-first convention)
- Uremic polyneuropathy (in certain documentation scenarios — see sequencing rules below)
- Neuropathy due to systemic amyloidosis (when a more specific amyloid neuropathy code is not applicable)
- Small fiber neuropathy confirmed by skin punch biopsy when no other code captures it
What Does G62.89 Specifically Exclude?
G62.89 is excluded when a more specific code exists. Do not assign G62.89 for:
- G62.0 — Drug-induced polyneuropathy (requires additional T-code for the causal drug)
- G62.1 — Alcoholic polyneuropathy
- G62.2 — Polyneuropathy due to other toxic agents
- G62.81 — Critical illness polyneuropathy
- G62.82 — Radiation-induced polyneuropathy
- G63 — Polyneuropathy in diseases classified elsewhere (e.g., diabetic polyneuropathy — code the underlying disease first)
- Any hereditary neuropathy falling within the G60 category
When Is G62.89 the Right Code to Use?
In practice, the decision to land on G62.89 follows a deliberate elimination process. Coders frequently encounter documentation that names a neuropathy clearly but doesn’t match any of the G62.0–G62.82 subcodes — that is where G62.89 earns its place. Use this code only after completing the following steps:
- Confirm a polyneuropathy is documented. The condition must involve multiple peripheral nerves. Single-nerve involvement (mononeuropathy) routes to different categories (G56–G58).
- Verify the provider has named the polyneuropathy. If the notes say only “neuropathy” or “polyneuropathy” without further characterization, use G62.9 (unspecified) instead.
- Search for a more specific subcategory. Work through G62.0–G62.82 systematically. If the documented etiology (drug, alcohol, toxin, critical illness, radiation) maps to a sibling code, use that code instead.
- Check whether the condition is a manifestation of an underlying disease. If so, the ICD-10-CM convention requires coding the underlying condition first, with G62.89 (or G63) as a secondary code.
- Confirm no hereditary or inflammatory neuropathy code (G60–G61 category) is more appropriate. CIDP, for instance, maps to G61.81.
- Assign G62.89 only when the named polyneuropathy has no more specific home in the classification.
How Does G62.89 Differ From G62.9 (Polyneuropathy, Unspecified)?
This is the most common source of coding confusion in the G62 family. The distinction is not clinical severity — it is documentation specificity.
| Feature | G62.89 | G62.9 |
|---|---|---|
| Provider has named the condition | Yes — specific type documented | No — only “polyneuropathy” or “neuropathy NOS” |
| NEC vs. NOS designation | NEC (not elsewhere classifiable) | NOS (not otherwise specified) |
| Audit risk | Lower — specificity is documented | Higher — payers scrutinize unspecified codes |
| Provider query recommended? | Usually no — condition is named | Yes — query to determine if type can be specified |
| Acceptable as principal dx? | Yes, when etiology is the named condition | Yes, but expect payer push-back without supporting documentation |
What Documentation Is Required to Support G62.89?
G62.89 carries an implicit documentation burden: the provider must have done more than write “peripheral neuropathy” in the assessment. Auditors reviewing claims with this code will look for the clinical narrative that justifies the specified designation. Without it, the code cannot stand.
What Must the Provider Document in the Clinical Notes?
- Named diagnosis — The provider must explicitly use a clinical term beyond “polyneuropathy” (e.g., “multifocal motor neuropathy,” “anoxic neuropathy,” “autoimmune peripheral motor neuropathy”)
- Symptom description — Distribution (distal vs. proximal, symmetric vs. asymmetric), sensory vs. motor vs. mixed involvement, and functional impact
- Clinical rationale — Why the specific neuropathy type was determined (e.g., immunologic workup, electrodiagnostic pattern, biopsy result)
- Etiology statement — If a systemic condition contributes, it must be explicitly linked (e.g., “polyneuropathy in the context of systemic lupus erythematosus”)
- Treatment plan — IVIg initiation, plasma exchange, or specific pharmacologic agents that reinforce the clinical specificity of the diagnosis
Which Diagnostic or Lab Results Support This Code?
Supporting workup findings that substantiate G62.89 include:
- Nerve conduction studies (NCS) and electromyography (EMG) — the primary electrodiagnostic backbone; must show multineuropathic pattern
- Anti-GM1 antibody titer — elevated in multifocal motor neuropathy
- CSF analysis — elevated protein in inflammatory or autoimmune neuropathies
- Skin punch biopsy with epidermal nerve fiber density count — for small fiber neuropathy variants
- Anti-nuclear antibody (ANA), anti-Ro/La, ANCA panels — supporting autoimmune etiology
- Serum protein electrophoresis (SPEP) / immunofixation — for paraprotein-associated neuropathy
What Is the Documentation Standard for Inpatient vs. Outpatient Settings?
| Setting | Standard | Notes |
|---|---|---|
| Outpatient | Condition must be confirmed — code only confirmed diagnoses | “Probable” or “suspected” polyneuropathy cannot be coded as G62.89 in outpatient |
| Inpatient | Conditions described as “probable” or “suspected” at discharge may be coded | Per ICD-10-CM Official Coding Guidelines Section II, inpatient coders may code uncertain diagnoses |
| Both settings | Provider’s named diagnosis drives code selection — coder cannot infer specificity | If unsure, query the provider before assigning G62.89 over G62.9 |
How Does G62.89 Affect Medical Billing and Claims?
G62.89 maps to MS-DRG 073 or 074 depending on whether a major complication or comorbidity (MCC) is present. For outpatient and professional claims, the DRG designation doesn’t apply, but the code still drives medical necessity documentation requirements that payers evaluate during claims processing and retrospective audits.
Key payer and billing considerations:
- G62.89 is generally covered by Medicare when medical necessity is established — the clinical record must support the named, specific neuropathy diagnosis
- Commercial payers may apply Local Coverage Determinations (LCDs) to neurology services billed with this code; review your MAC’s LCD for electrodiagnostic studies (e.g., NCS/EMG), which are commonly ordered alongside
- When G62.89 is a secondary diagnosis reflecting a manifestation of an underlying disease, payers expect to see the primary etiology code sequenced first — failure to sequence correctly is a common denial trigger
- Some payers have specific medical necessity criteria for IVIg treatment when coded with G62.89 — prior authorization requirements vary by plan
What CPT or Procedure Codes Are Commonly Billed With G62.89?
| CPT Code | Description | Typical Pairing Context |
|---|---|---|
| 95907–95913 | Nerve conduction studies (1–12+ studies) | Initial diagnostic workup |
| 95860–95864 | Needle electromyography (EMG) | EMG confirmation of multineuropathic pattern |
| 99213–99215 | Office E&M visits | Ongoing neurology management |
| 96365–96368 | IV infusion (e.g., IVIg) | Treatment of autoimmune polyneuropathy variants |
| 86255 | Anti-GM1 antibody | Workup for multifocal motor neuropathy |
| 95905 | Motor and sensory nerve testing (motor evoked) | Advanced electrodiagnostic protocols |
Are There Any Prior Authorization or Coverage Restrictions?
- IVIg (96365): Most commercial payers and many Medicare Advantage plans require prior authorization when billing IVIg for polyneuropathy — G62.89 alone may be insufficient; specific neuropathy subtype documentation is often required
- NCS/EMG: CMS and most MACs cover electrodiagnostic studies for G62.89 when medically necessary; frequency limitations apply (typically limited to one complete study per episode)
- Skin punch biopsy for small fiber neuropathy: Coverage is inconsistent — check applicable LCD (e.g., L38484 in some jurisdictions) before billing
What Coding Errors Should You Avoid With G62.89?
G62.89 is a high-utility code, but its “catch-all” nature invites misuse. The following errors appear most frequently in chart audits and claim denials:
- Using G62.89 when G62.9 is correct — If the provider wrote only “polyneuropathy” or “peripheral neuropathy” without naming a specific type, G62.9 is the appropriate code. G62.89 requires documented specificity; you cannot assign it based on clinical inference alone.
- Skipping the code-first convention for manifestation codes — When polyneuropathy is documented as a manifestation of diabetes, amyloidosis, or another systemic condition, the underlying disease must be sequenced first. Placing G62.89 as the primary diagnosis in this scenario is a sequencing error.
- Coding G62.89 when a sibling code exists — Drug-induced neuropathy goes to G62.0 (with a causative T-code), radiation-induced to G62.82, critical illness to G62.81. Defaulting to G62.89 without checking the full subcategory is a hierarchy error.
- Including the decimal point on electronic claims — Submit as G6289, not G62.89. The decimal is for human-readable use only and can cause claim rejection at the clearinghouse.
- Failing to document the etiology linkage — If the neuropathy is tied to a systemic disease, that linkage must be explicit in the provider’s note. Coders cannot create clinical connections not stated in the record.
What Do Auditors Look for When Reviewing Claims With G62.89?
- Provider note contains only generic terms (“neuropathy,” “nerve pain”) without a named subtype — signals G62.9 may have been the appropriate code
- G62.89 sequenced as primary when an underlying systemic condition is documented — etiology-first convention violation
- IVIg billed (96365) with G62.89 and no prior auth or clinical criteria documentation in the record
- Repeat NCS/EMG studies billed within the same episode without documented change in clinical status
- Absence of diagnostic workup results in the record that substantiate the specific neuropathy type
How Does G62.89 Relate to Other ICD-10 Codes?
Understanding where G62.89 sits within the broader polyneuropathy coding landscape prevents both undercoding and overcoding.
| ICD-10 Code | Condition | Relationship to G62.89 | Key Distinction |
|---|---|---|---|
| G62.0 | Drug-induced polyneuropathy | Excludes 1 (use instead) | Requires documented causative drug + T-code |
| G62.1 | Alcoholic polyneuropathy | Excludes 1 (use instead) | Alcohol documented as cause |
| G62.2 | Polyneuropathy due to other toxic agents | Excludes 1 (use instead) | Toxic etiology documented |
| G62.81 | Critical illness polyneuropathy | Excludes 1 (use instead) | ICU setting, documented CIP/CIM |
| G62.82 | Radiation-induced polyneuropathy | Excludes 1 (use instead) | Radiation as documented etiology |
| G62.9 | Polyneuropathy, unspecified | Sibling (use when unspecified) | No named subtype in documentation |
| G61.81 | CIDP | Separate category — use instead | Chronic inflammatory demyelinating polyneuropathy has its own code |
| G63 | Polyneuropathy in diseases classified elsewhere | Manifestation code — use with etiology first | The underlying disease is primary |
| G60.3 | Idiopathic progressive neuropathy | Separate subcategory | Idiopathic and progressive — no identifiable cause |
What Is the Correct Code Sequencing When G62.89 Appears With Other Diagnoses?
- Manifestation scenario: Code the underlying etiology (e.g., E11.40 for diabetic neuropathy) first; G62.89 or G63 follows as a secondary code. The “code first” and “use additional code” notes in the Tabular List govern this.
- Standalone scenario: When G62.89 reflects the primary reason for the encounter (e.g., a named autoimmune polyneuropathy managed at a neurology visit), G62.89 may be sequenced as the principal or first-listed diagnosis.
- Multiple conditions: When a patient has both a contributing systemic disease and a specifically named polyneuropathy that is a separate condition (not a direct manifestation), both may be coded — sequence by the circumstance of the visit per ICD-10-CM Official Coding Guidelines Section III (Outpatient) or Section II (Inpatient).
Real-World Coding Scenario — How G62.89 Is Applied in Practice
Patient encounter: A 58-year-old male presents to neurology for follow-up of progressively worsening proximal and distal upper extremity weakness without sensory loss. NCS performed three months prior confirmed multifocal conduction block at multiple non-compression sites. Anti-GM1 IgM antibody is elevated at 1:3200. The neurologist documents the assessment as: “Multifocal motor neuropathy (MMN) — initiating IVIg therapy.” The encounter also notes longstanding hypertension (I10), which is unrelated to the neuropathy.
Correct Code Application
- G62.89 — Primary diagnosis: Multifocal motor neuropathy, a named polyneuropathy indexed directly to G62.89
- I10 — Secondary diagnosis: Essential hypertension (documented, managed separately)
- 96365 — IV infusion administration for IVIg
- 86255 — Anti-GM1 antibody (if billed during same encounter)
Common Mistake in This Scenario
- Incorrect code: G62.9 (Polyneuropathy, unspecified)
- Why it fails: The neurologist has explicitly named the condition as multifocal motor neuropathy — using the unspecified code discards documented clinical specificity, increases audit risk, may trigger a medical necessity denial for IVIg, and is a diagnosis code specificity violation under ICD-10-CM Official Coding Guidelines
Frequently Asked Questions About ICD-10 Code G62.89
Is ICD-10 Code G62.89 Valid for Use in 2026?
G62.89 is a valid, billable ICD-10-CM code for fiscal year 2026, effective October 1, 2025 through September 30, 2026, with no changes to its description or validity status. Coders should verify annually against the CMS ICD-10-CM tabular file to confirm no revisions have been applied.
What Is the Difference Between G62.89 and G62.9?
G62.89 is used when the provider has named a specific type of polyneuropathy that lacks its own dedicated ICD-10 code, while G62.9 is reserved for cases where the documentation contains no qualifying specificity beyond “polyneuropathy.” The choice between them is driven entirely by what the provider has documented — coders cannot upgrade G62.9 to G62.89 without explicit clinical support in the record.
Can G62.89 Be Used as a Primary Diagnosis?
G62.89 can be sequenced as the primary or first-listed diagnosis when the named polyneuropathy is the reason for the encounter and is not a manifestation of an underlying systemic disease. When it represents a complication or manifestation of another condition (such as amyloidosis or a connective tissue disorder), the etiology code must be listed first per the ICD-10-CM code-first convention.
What Documentation Does a Provider Need to Justify G62.89?
The provider must document a named polyneuropathy diagnosis — not just symptoms — along with clinical reasoning supporting that specific diagnosis. Electrodiagnostic study results, relevant laboratory findings (such as antibody titers), and a clear statement of the condition type in the assessment section of the note are the core documentation elements payers and auditors expect to find.
Does Medicare Cover Services Billed With G62.89?
Medicare covers diagnostic and therapeutic services billed with G62.89 when medical necessity is established and the clinical record supports the named diagnosis. Coverage for associated services like IVIg and repeated electrodiagnostic studies may require prior authorization under Medicare Advantage plans, and Medicare Local Coverage Determinations applicable to neurology services in your jurisdiction should be reviewed.
When Should I Query the Provider Instead of Using G62.89?
A provider query is appropriate when the clinical notes describe neuropathy symptoms, test results, or a treatment plan consistent with a specific polyneuropathy type, but the provider has only written “polyneuropathy” in the assessment. Coders should not infer specificity from diagnostic findings alone — the provider must make the clinical determination. When in doubt, query to determine whether a more specific named diagnosis can be documented.
Key Takeaways
- G62.89 is the appropriate code for a named, specific polyneuropathy that does not map to any other more specific ICD-10-CM subcategory — it is an NEC code, not a catch-all for vague documentation
- G62.89 and G62.9 are frequently confused; the distinction is entirely documentation-driven — specificity in the provider’s assessment is the deciding factor
- Always check sibling codes (G62.0, G62.1, G62.2, G62.81, G62.82) and parent category G63 before landing on G62.89
- When polyneuropathy is a manifestation of an underlying disease, the etiology code must be sequenced first per standard ICD-10-CM conventions
- Supporting diagnostic findings (NCS/EMG, antibody titers, biopsy) should be present in the record but cannot substitute for the provider’s explicit named diagnosis
- For electronic claims submission, omit the decimal point — submit as G6289
- For coding audit preparation, ensure the clinical note contains a named diagnosis, supporting workup, and an etiology statement; auditors flag G62.89 claims that rest on generic documentation
- For deeper guidance on sequencing polyneuropathy with systemic diseases, consult the AHA Coding Clinic and the ICD-10-CM Official Coding Guidelines published annually by CMS