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ICD-10 Guide
ICD-10 CodesChapter 6: Diseases of the nervous systemG99

G99

Billable

Other disorders of nervous system in diseases classified elsewhere

Chapter 6:Diseases of the nervous system

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/05/2025

Code Description

ICD-10 G99 is a billable code used to indicate a diagnosis of other disorders of nervous system in diseases classified elsewhere.

Key Diagnostic Point:

The G99 code encompasses a variety of disorders affecting the nervous system that are classified under other diseases. This includes pain syndromes such as neuropathic pain, which can arise from conditions like diabetes or post-herpetic neuralgia. Autonomic disorders, which affect involuntary bodily functions, may also fall under this code, including conditions like dysautonomia. Hydrocephalus, characterized by an accumulation of cerebrospinal fluid within the ventricles of the brain, can lead to increased intracranial pressure and neurological deficits. Other nervous system disorders that may be coded under G99 include conditions resulting from systemic diseases, infections, or trauma that do not have a specific code in the ICD-10 classification. Accurate coding requires a thorough understanding of the underlying conditions and their manifestations, as well as the documentation provided by healthcare providers.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variety of underlying conditions leading to similar symptoms
  • Need for precise documentation to determine the primary diagnosis
  • Potential overlap with other specific codes
  • Variability in clinical presentation

Audit Risk Factors

  • Inadequate documentation of the primary diagnosis
  • Misinterpretation of symptoms leading to incorrect coding
  • Failure to link the disorder to the underlying disease
  • Inconsistent coding practices among different providers

Specialty Focus

Medical Specialties

Neurology

Documentation Requirements

Detailed neurological examination findings, history of present illness, and any diagnostic imaging results.

Common Clinical Scenarios

Patients presenting with chronic pain syndromes, autonomic dysfunction, or post-surgical complications.

Billing Considerations

Ensure that the primary condition is clearly documented to support the use of G99.

Pain Management

Documentation Requirements

Comprehensive pain assessments, treatment plans, and response to therapies.

Common Clinical Scenarios

Management of neuropathic pain or complex regional pain syndrome.

Billing Considerations

Document the relationship between pain syndromes and any underlying conditions to justify the use of G99.

Coding Guidelines

Inclusion Criteria

Use G99 When
  • According to ICD
  • 10 guidelines, G99 should be used when the nervous system disorder is a consequence of a disease classified elsewhere
  • Coders must ensure that the primary diagnosis is clearly documented and that the G99 code is not used as a primary diagnosis

Exclusion Criteria

Do NOT use G99 When
No specific exclusions found.

Related CPT Codes

99214CPT Code

Established patient office visit, level 4

Clinical Scenario

Used for follow-up visits for patients with chronic pain syndromes.

Documentation Requirements

Detailed history, examination, and medical decision-making.

Specialty Considerations

Neurology and pain management specialties should ensure comprehensive documentation to support the visit level.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of nervous system disorders, enabling better tracking of conditions like neuropathic pain and autonomic disorders. G99 serves as a catch-all for disorders that do not fit neatly into other categories, emphasizing the need for precise documentation.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of nervous system disorders, enabling better tracking of conditions like neuropathic pain and autonomic disorders. G99 serves as a catch-all for disorders that do not fit neatly into other categories, emphasizing the need for precise documentation.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more specific coding of nervous system disorders, enabling better tracking of conditions like neuropathic pain and autonomic disorders. G99 serves as a catch-all for disorders that do not fit neatly into other categories, emphasizing the need for precise documentation.

Resources

Clinical References

  • •
    ICD-10-CM Official Guidelines for Coding and Reporting

Coding & Billing References

  • •
    ICD-10-CM Official Guidelines for Coding and Reporting

Frequently Asked Questions

When should I use G99?

G99 should be used when a nervous system disorder is a consequence of a disease classified elsewhere, and the primary diagnosis is clearly documented.