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2025 ICD-10-CM Diagnosis Code G94

Other disorders of brain in diseases classified elsewhere

ICD-10-CM Code:
G94
ICD-10 Code for:
Other disorders of brain in diseases classified elsewhere
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Not chronic
Code Navigator:

G94 is a billable diagnosis code used to specify a medical diagnosis of other disorders of brain in diseases classified elsewhere. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2024 through September 30, 2025.

Code Classification

  • Diseases of the nervous system
    (G00–G99)
    • Other disorders of the nervous system
      (G89-G99)
      • Other disorders of brain in diseases classified elsewhere
        (G94)

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

  • Acquired ataxia
  • Autoimmune movement disorder
  • Autoimmune thyroiditis
  • Cortical blindness
  • Developmental and epileptic encephalopathy
  • Early-onset epileptic encephalopathy and intellectual disability due to GRIN2A mutation
  • Early-onset epileptic encephalopathy, cortical blindness, intellectual disability, facial dysmorphism syndrome
  • Encephalopathy caused by monkeypox virus
  • Epileptic encephalopathy
  • FASTKD2-related infantile mitochondrial encephalomyopathy
  • Human immunodeficiency virus encephalopathy
  • Infantile epileptic dyskinetic encephalopathy
  • Intracranial hypotension
  • Intracranial hypotension due to lumbar puncture
  • Neurological disorder due to and following lumbar puncture
  • RNF13-related severe early-onset epileptic encephalopathy
  • Steroid-responsive encephalopathy associated with autoimmune thyroiditis
  • SYNGAP1-related developmental and epileptic encephalopathy

Clinical Classification

Clinical Classifications group individual ICD-10-CM diagnosis codes into broader, clinically meaningful categories. These categories help simplify complex data by organizing related conditions under common clinical themes.

They are especially useful for data analysis, reporting, and clinical decision-making. Even when diagnosis codes differ, similar conditions can be grouped together based on their clinical relevance. Each category is assigned a unique CCSR code that represents a specific clinical concept, often tied to a body system or medical specialty.

Other nervous system disorders (neither hereditary nor degenerative)

CCSR Code: NVS020

Inpatient Default: X - Not applicable.

Outpatient Default: X - Not applicable.

Clinical Information

  • Intracranial Hypotension

    reduction of cerebrospinal fluid pressure characterized clinically by orthostatic headache and occasionally by an abducens nerve palsy; hearing loss; nausea; neck stiffness, and other symptoms. this condition may be spontaneous or secondary to cerebrospinal fluid leak; spinal puncture; neurosurgical procedures; dehydration; uremia; trauma (see also craniocerebral trauma); and other processes. chronic hypotension may be associated with subdural hematomas (see hematoma, subdural) or hygromas. (from semin neurol 1996 mar;16(1):5-10; adams et al., principles of neurology, 6th ed, pp637-8)

  • Cortical Blindness

    visual impairment due to visual cortex dysfunction.

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Code First

Code First
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
  • underlying disease

Type 1 Excludes

Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • encephalopathy in congenital syphilis A50.49
  • encephalopathy in influenza J09.X9 J10.81 J11.81
  • encephalopathy in syphilis A52.19
  • hydrocephalus in diseases classified elsewhere G91.4

Code Edits

The Medicare Code Editor (MCE) detects errors and inconsistencies in ICD-10-CM diagnosis coding that can affect Medicare claim validity. These Medicare code edits help medical coders and billing professionals determine when a diagnosis code is not appropriate as a principal diagnosis, does not meet coverage criteria. Use this list to verify whether a code is valid for Medicare billing and to avoid claim rejections or denials due to diagnosis coding issues.

Manifestation diagnoses

Manifestation codes describe the manifestation of an underlying disease, not the disease itself, and therefore should not be used as a principal diagnosis.

View Edit

Convert G94 to ICD-9-CM

Below are the ICD-9 codes that most closely match this ICD-10 code, based on the General Equivalence Mappings (GEMs). This ICD-10 to ICD-9 crosswalk tool is helpful for coders who need to reference legacy diagnosis codes for audits, historical claims, or approximate code comparisons.

Cereb degen in oth dis

ICD-9-CM: 331.7

Approximate Flag - The approximate mapping means this ICD-10 code does not have an exact ICD-9 equivalent. The matched code is the closest available option, but it may not fully capture the original diagnosis or clinical intent.

View Conversion

Patient Education


Brain Diseases

Your brain is the control center of your body. It controls your thoughts, memory, speech, and movement. It regulates the function of many organs. It's part of your nervous system, which also includes your spinal cord and peripheral nerves. The nervous system sends signals between your brain and the rest of the body. Your nerves take in information from your senses and send it to the brain to be processed. Your brain and nerves also communicate to help you move and to control your body's functions.

When the brain is healthy, it works quickly and automatically. But when you have a brain disease, it may affect how well you can function and do your daily activities. Some common brain diseases include:

  • Brain tumors, which can press on nerves and affect brain function.
  • Degenerative nerve diseases, which can affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Types include Alzheimer's disease and Parkinson's disease.
  • Encephalitis (inflammation in the brain), which can lead to problems such as vision loss, weakness, and paralysis.
  • Genetic brain disorders, which are caused by changes in genes (also called variants or mutations). These disorders can affect the development and function of the brain.
  • Strokes, which can cause a loss of brain cells and can affect your ability to think clearly.
  • Traumatic brain injuries (TBIs), which can affect brain function. They may range from mild to severe. The effects of a TBI may be temporary or permanent.

The symptoms of brain diseases vary widely, depending on the specific problem. In some cases, damage is permanent. In other cases, treatments such as surgery, medicines, or therapies such as physical, occupational, and speech therapies, may cure the disease or improve the symptoms.


[Learn More in MedlinePlus]

Code History

  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.