M79.2

🧬 ICD-10 CM M79.2 — Neuralgia and Neuritis, Unspecified

Billable Code Confirmed

ICD-10 CM M79.2 is a complete, four-character ICD-10-CM code and is fully billable on inpatient and outpatient claims for FY2026.³ The code requires no additional digits, though coders should always verify the record does not support a more specific mononeuropathy or radiculopathy diagnosis before defaulting to this unspecified code.

Clinical Context

Providers select M79.2 when a patient reports nerve pain or inflammation consistent with neuralgia or neuritis, but the documentation does not identify a specific nerve, root, or underlying autoimmune process.

Code Classification

ICD-10 CM M79.2 is a diagnosis code used to classify nonspecific nerve pain or nerve inflammation; it is not a procedure code and carries no inherent HCC weight or DRG severity impact.

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🔍 Code Description

ICD-10 CM M79.2 falls within the M79 category of “Other and unspecified soft tissue disorders,” positioned in the M70-M79 block alongside codes like M79.0 (rheumatism, unspecified) and M79.1-family myalgia codes. Unlike myalgia, which describes muscular pain, M79.2 specifically addresses pain or dysfunction arising from nerve tissue itself, encompassing both neuralgia (pain along a nerve distribution) and neuritis (nerve inflammation) when the exact nerve or cause is not documented.

Because M79.2 is defined broadly, coders must carefully distinguish it from more specific neurologic diagnoses classified outside Chapter 13, such as mononeuropathies coded under G56 or G58, or radiculitis coded under M54.1. When a provider’s documentation supports a defined nerve root or peripheral nerve involvement, that more specific code should be used instead of M79.2, since it better reflects the clinical picture and may carry greater specificity value for quality reporting. Sciatica, coded under M54.3 or M54.4, is also explicitly excluded and must never be confused with generalized neuralgia.

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🌳 Code Tree / Hierarchy

M79 Other and unspecified soft tissue disorders, not elsewhere classified ❌ Non-billable
│
├── M79.0 Rheumatism, unspecified ✅ Billable
├── M79.1 Myalgia ❌ Non-billable
│ │
│ ├── M79.10 Myalgia, unspecified site ✅ Billable
│ └── M79.18 Myalgia, other site ✅ Billable
│
├── M79.2 Neuralgia and neuritis, unspecified ◀ THIS CODE ✅ Billable
│
├── M79.6- Pain in limb, hand, foot, fingers and toes ✅ Billable
└── M79.7 Fibromyalgia ✅ Billable

Specificity Matters

Payers may question repeated use of M79.2 without a documented workup, since a persistent nerve pain complaint often warrants electromyography or nerve conduction studies that could support a more specific mononeuropathy diagnosis under G56 or G58.

Tip

Always rule out sciatica (M54.3x or M54.4x) and true mononeuropathies before defaulting to M79.2, since these are Excludes1 conditions that cannot be coded alongside this code.

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✅ Includes

• Atypical neuralgia without a documented specific cause or nerve
• Autoimmune neuritis of unspecified type or nerve distribution
• Generalized nerve pain not attributable to a specific mononeuropathy, radiculopathy, or sciatica

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❌ Excludes

Excludes 1

• M54.1x — Radiculitis NOS, brachial radiculitis NOS, and lumbosacral radiculitis NOS describe nerve root inflammation with distinct anatomic specificity and cannot be coded together with M79.2; this code requires additional characters to be billable.
• G56/G58 — Mononeuropathies of the upper limb and other mononeuropathies represent confirmed single-nerve pathology, typically supported by nerve conduction studies, and are excluded because they are far more clinically specific than M79.2.
• M54.3x/M54.4x — Sciatica and lumbago with sciatica describe a well-defined nerve distribution pattern along the sciatic nerve and must never be coded as generalized neuralgia.

Danger

The most common Excludes1 error occurs when a clinician documents “sciatic neuralgia,” prompting coders to default to M79.2 instead of correctly assigning M54.3x or M54.4x, which better reflects the specific nerve distribution involved.

Excludes 2

• F45.8 — Psychogenic rheumatism may be coded in addition to M79.2 when a documented psychological component contributes to the nerve pain presentation independently of the physical etiology.
• F45.41 — Soft tissue pain, psychogenic, may also be reported alongside M79.2 when psychological factors are separately documented as contributing to the pain experience.

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📋 Clinical Overview

Unspecified Neuralgia vs. Specific Mononeuropathy

ICD-10 CM M79.2 and confirmed mononeuropathies under G56 or G58 both describe nerve pain, but differ substantially in diagnostic certainty and workup depth.

Feature	M79.2	M79.0	M79.7
Primary symptom	Nerve pain or inflammation without a documented specific nerve.	Generalized rheumatic aching or stiffness without confirmed cause.	Widespread chronic pain with defined tender point criteria.
Diagnostic specificity	Low; used when nerve conduction studies are not performed or inconclusive.	Very low; nonspecific rheumatic complaint.	High; requires established diagnostic criteria over three months.
Typical care setting	Primary care, neurology, pain management.	Primary care, urgent care.	Rheumatology specialty clinics.

Important

A CDI trigger should fire whenever “neuralgia” or “neuritis” appears without any accompanying nerve conduction study, EMG, or neurology referral, since this often signals an opportunity to clarify a more specific and clinically meaningful diagnosis.

Manifestations & Symptom Burden

• Sharp, shooting, or burning pain along an undefined nerve distribution.
• Tingling or numbness accompanying the nerve pain without confirmed dermatomal pattern.
• Hypersensitivity to touch in the affected area without a documented autoimmune or metabolic cause.

Tip

Manifestation-level symptoms such as tingling or numbness should not be separately coded when they are integral to the neuralgia presentation itself; only code them separately if documented as distinct, unrelated findings.

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💰 HCC Risk Adjustment

ICD-10 CM M79.2 does not map to any CMS-HCC category under the current V28 model, meaning it carries no RAF value and has no impact on Medicare Advantage risk scores.¹ Coders should still capture it for clinical completeness, but should prioritize identifying and documenting any underlying HCC-eligible neurologic condition whenever supported by the record.

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🏥 MS-DRG Assignment

ICD-10 CM M79.2 is not a CC or MCC and does not independently influence MS-DRG grouping or the assigned relative weight.² It is typically reported as a secondary diagnosis alongside the condition that actually justified inpatient admission, since nonspecific neuralgia rarely meets inpatient severity thresholds on its own.

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🔗 Related ICD-10-CM Codes

Soft tissue disorder group: M79.0 (rheumatism, unspecified), M79.10 (myalgia, unspecified site), M79.18 (myalgia, other site), M79.7 (fibromyalgia).

Neurologic alternatives to consider when specificity is available: M54.3x (sciatica), M54.4x (lumbago with sciatica), M54.1x is non-billable and requires additional characters, and confirmed mononeuropathy codes under the G56/G58 range also require further specificity before billing.

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🛠️ Commonly Associated CPT Codes

• 99213 — Established patient office visit, low complexity; frequently billed alongside M79.2 for routine neuralgia follow-up.
• 99203 — New patient office visit, low complexity; used when M79.2 is first assigned during an initial evaluation.
• 95907 — Nerve conduction study, one to two studies; reported when a workup is performed to rule out a specific mononeuropathy before finalizing M79.2.
• 64450 — Injection, anesthetic agent, other peripheral nerve or branch; may be reported if a diagnostic or therapeutic nerve block is performed for symptomatic relief.

NCCI Bundling Considerations

Evaluation and management codes billed with a same-day nerve block such as 64450 may require modifier -25 to indicate a significant, separately identifiable service, since NCCI edits can otherwise bundle the E/M into the procedure. Nerve conduction studies like 95907 are not typically bundled with routine office visits when medical necessity is clearly documented.

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🔬 ICD-10-PCS Crosswalk

ICD-10 CM M79.2 is a diagnosis code and has no direct ICD-10-PCS procedural crosswalk, since PCS codes classify inpatient procedures rather than symptom-based diagnoses.

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💊 Coding Scenarios and Examples

Scenario 1: A 52-year-old presents to primary care with burning nerve pain in the forearm for one week, and nerve conduction studies were not performed. Correct coding: M79.2. Sequencing: reported as the primary diagnosis for this encounter since no specific nerve or cause is confirmed.

Scenario 2: A patient with documented sciatica describes symptoms in the note as “leg neuralgia.” Correct coding: M54.3x, not M79.2, per the Excludes1 instruction. CDI note: query the provider to confirm the diagnosis reflects sciatica rather than the nonspecific neuralgia language used colloquially.

Scenario 3: An inpatient admitted for a stroke also has a longstanding history of unspecified neuralgia noted in the past medical history with no active treatment during the stay. Correct coding: stroke code sequenced first, M79.2 listed as a secondary diagnosis. Sequencing explanation: M79.2 does not meet reporting criteria as a principal diagnosis here and carries no CC/MCC weight.

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⚠️ Coding Pitfalls and Tips

• Do not default to M79.2 simply because a patient describes “nerve pain”; always check documentation for a more specific supportable diagnosis such as a confirmed mononeuropathy or radiculopathy first.
• Remember the Excludes1 relationship with M54.3x and M54.4x; sciatica and unspecified neuralgia cannot both be coded for the same encounter.
• M79.2 carries no HCC weight and no CC/MCC status, so it will not affect risk scores or DRG weighting.
• Psychogenic contributors coded under F45.8 or F45.41 may be reported in addition to M79.2 when clearly documented as a separate, contributing factor rather than the sole cause.

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^{Sources: ¹CMS-HCC Model V28 Risk Adjustment Documentation, cms.gov · ²CMS MS-DRG Definitions Manual, FY2026 · ³CMS/NCHS ICD-10-CM FY2026 Tabular List, cms.gov · ⁴ICD-10-CM Official Guidelines for Coding and Reporting, FY2026}