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ICD10BillableValid for clinical use

ICD-10 Code G91.4: Hydrocephalus in diseases classified elsewhere

G91.4 is a billable ICD-10 diagnosis code used to classify Hydrocephalus in diseases classified elsewhere in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the nervous system (G00-G99).

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Diseases of the nervous system (G00-G99).

When is it used?

  • May be used when a clinician documents hydrocephalus in diseases classified elsewhere in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
6Diseases of the nervous system (G00-G99)
block
G89-G99Other disorders of the nervous system
category
G91Hydrocephalus
currentG91

Official coding notes

Applicable to
  • underlying condition, such as:
  • congenital syphilis (A50.4-)
  • neoplasm (C00-D49)
  • plasminogen deficiency (E88.02)
Excludes1 (do not code together)
  • hydrocephalus due to congenital toxoplasmosis (P37.1)
Code first
  • underlying condition, such as:
  • congenital syphilis (A50.4-)
  • neoplasm (C00-D49)
  • plasminogen deficiency (E88.02)

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

NeurologistGeneral Physician

Coverage-related procedures and services

CPT 70460high
COMPUTED TOMOGRAPHY, HEAD OR BRAIN; WITH CONTRAST MATERIAL(S)
Source: CMS coverage guidance
CPT 70450high
COMPUTED TOMOGRAPHY, HEAD OR BRAIN; WITHOUT CONTRAST MATERIAL
Source: CMS coverage guidance
CPT 70470high
COMPUTED TOMOGRAPHY, HEAD OR BRAIN; WITHOUT CONTRAST MATERIAL, FOLLOWED BY CONTRAST MATERIAL(S) AND FURTHER SECTIONS
Source: CMS coverage guidance
CPT 96105high
ASSESSMENT OF APHASIA (INCLUDES ASSESSMENT OF EXPRESSIVE AND RECEPTIVE SPEECH AND LANGUAGE FUNCTION, LANGUAGE COMPREHENSION, SPEECH PRODUCTION ABILITY, READING, SPELLING, WRITING, EG, BY BOSTON DIAGNOSTIC APHASIA EXAMINATION) WITH INTERPRETATION AND REPORT, PER HOUR
Source: CMS coverage guidance
CPT 92524high
BEHAVIORAL AND QUALITATIVE ANALYSIS OF VOICE AND RESONANCE
Source: CMS coverage guidance
CPT 72126high
COMPUTED TOMOGRAPHY, CERVICAL SPINE; WITH CONTRAST MATERIAL
Source: CMS coverage guidance

Coding guidelines

Common synonyms

Hydrocephalus in diseases classified elsewhere

Frequently asked questions

Code details

CodeG91.4
SystemICD10
Display nameHydrocephalus in diseases classified elsewhere
ChapterDiseases of the nervous system (G00-G99)
BlockOther disorders of the nervous system

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Hydrocephalus(acquired) (external) (internal) (malignant) (recurrent)Hydrocephalus(acquired) (external) (internal) (malignant) (recurrent)Hydrocephalus(acquired) (external) (internal) (malignant) (recurrent)Hydrocephalus(acquired) (external) (internal) (malignant) (recurrent)

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.