1. Home
  2. ICD-10-CM Codes
  3. G00–G99
  4. G40-G47
  5. G46
  6. 2026 ICD-10-CM Code G46.3

2026 ICD-10-CM Diagnosis Code G46.3

Brain stem stroke syndrome

ICD-10-CM Code:
G46.3
ICD-10 Code for:
Brain stem stroke syndrome
Is Billable?
Yes - Valid for Submission
Chronic Condition Indicator: [1]
Chronic
Code Navigator:

G46.3 is a billable diagnosis code used to specify a medical diagnosis of brain stem stroke syndrome. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026.

Code Classification

  • Diseases of the nervous system
    G00–G99
    • Episodic and paroxysmal disorders
      G40-G47
      • Vascular syndromes of brain in cerebrovascular diseases
        G46

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.

  • Alternating hemiplegia
  • Benedikt's syndrome
  • Brain stem infarction
  • Brainstem stroke syndrome
  • Brainstem stroke syndrome
  • Cerebellar infarction
  • Claude's syndrome
  • Foville syndrome
  • Injury of facial nerve
  • Millard-Gubler syndrome
  • Paresis of extraocular muscles
  • Posterior cerebral circulation infarction
  • Posterior cerebral circulation infarction
  • Posterior cerebral circulation infarction
  • Posterior cerebral circulation infarction
  • Posterior inferior cerebellar artery syndrome
  • Supranuclear facial nerve paralysis
  • Supranuclear paralysis
  • Third cranial nerve finding

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 and ill-defined cerebrovascular disease

CCSR Code: CIR024

Inpatient Default: N - Not default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: N - Not default outpatient assignment for principal diagnosis or first-listed diagnosis.

Other nervous system disorders (neither hereditary nor degenerative)

CCSR Code: NVS020

Inpatient Default: Y - Yes, default inpatient assignment for principal diagnosis or first-listed diagnosis.

Outpatient Default: Y - Yes, default outpatient assignment for principal diagnosis or first-listed diagnosis.

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.


Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Benedikt syndrome
  • Claude syndrome
  • Foville syndrome
  • Millard-Gubler syndrome
  • Wallenberg syndrome
  • Weber syndrome

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Index of External Cause of Injuries

References found for this diagnosis code in the External Cause of Injuries Index:

    • Benedikt's paralysis or syndrome
    • Céstan(-Chenais) paralysis or syndrome
    • Claude's disease or syndrome
    • Foville's(peduncular) disease or syndrome
    • Gubler-Millard paralysis or syndrome
    • Millard-Gubler(-Foville) paralysis or syndrome
    • Paralysis, paralytic(complete) (incomplete)
      • Benedikt's
    • Paralysis, paralytic(complete) (incomplete)
      • Céstan-Chenais
    • Paralysis, paralytic(complete) (incomplete)
      • Gubler (-Millard)
    • Paralysis, paralytic(complete) (incomplete)
      • Millard-Gubler-Foville
    • Paralysis, paralytic(complete) (incomplete)
      • Weber's
    • Syndrome
      • Benedikt's
    • Syndrome
      • brain stem stroke
    • Syndrome
      • Foville's (peduncular)
    • Syndrome
      • Gubler-Millard
    • Syndrome
      • Millard-Gubler
    • Syndrome
      • Wallenberg's
    • Syndrome
      • Weber-Gubler
    • Syndrome
      • Weber-Leyden
    • Syndrome
      • Weber's
    • Wallenberg's disease or syndrome
    • Weber-Gubler syndrome
    • Weber-Leyden syndrome
    • Weber's paralysis or syndrome

Convert G46.3 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.

Cerebrovasc disease NEC

ICD-9-CM: 437.8

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 2026 - No Change, effective from 10/1/2025 through 9/30/2026
  • FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025
  • 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] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.