ICD-10-CM Code G45.9

Transient cerebral ischemic attack, unspecified

Version 2021 Billable Code

Valid for Submission

G45.9 is a billable code used to specify a medical diagnosis of transient cerebral ischemic attack, unspecified. The code is valid for the fiscal year 2021 for the submission of HIPAA-covered transactions. The ICD-10-CM code G45.9 might also be used to specify conditions or terms like arteriospasm, chronic cerebral ischemia, chronic vascular insufficiency, intermittent cerebral ischemia, recurrent transient cerebral ischemic attack, spasm of cerebral arteries, etc

Short Description:Transient cerebral ischemic attack, unspecified
Long Description:Transient cerebral ischemic attack, unspecified

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code G45.9:

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.
  • Spasm of cerebral artery
  • TIA
  • Transient cerebral ischemia NOS

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code G45.9 are found in the index:


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Arteriospasm
  • Chronic cerebral ischemia
  • Chronic vascular insufficiency
  • Intermittent cerebral ischemia
  • Recurrent transient cerebral ischemic attack
  • Spasm of cerebral arteries
  • Stroke/transient ischemic attack monitoring first letter
  • Stroke/transient ischemic attack monitoring invitation
  • Stroke/transient ischemic attack monitoring second letter
  • Stroke/transient ischemic attack monitoring status
  • Stroke/transient ischemic attack monitoring status
  • Stroke/transient ischemic attack monitoring status
  • Stroke/transient ischemic attack monitoring status
  • Stroke/transient ischemic attack monitoring status
  • Stroke/transient ischemic attack monitoring third letter
  • Stroke/transient ischemic attack monitoring verbal invitation
  • Transient cerebral ischemia
  • Transient cerebral ischemia due to atrial fibrillation
  • Transient ischemic attack due to embolism
  • Vasospasm

Convert G45.9 to ICD-9

  • 435.9 - Trans cereb ischemia NOS (Approximate Flag)

Code Classification

  • Diseases of the nervous system (G00–G99)
    • Episodic and paroxysmal disorders (G40-G47)
      • Transient cerebral ischemic attacks and related syndromes (G45)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Information for Patients

Transient Ischemic Attack

Also called: Mini-stroke, TIA

A transient ischemic attack (TIA) is a stroke that lasts only a few minutes. It happens when the blood supply to part of the brain is briefly blocked. Symptoms of a TIA are like other stroke symptoms, but do not last as long. They happen suddenly, and include

  • Numbness or weakness, especially on one side of the body
  • Confusion or trouble speaking or understanding speech
  • Trouble seeing in one or both eyes
  • Difficulty walking
  • Dizziness
  • Loss of balance or coordination

Most symptoms of a TIA disappear within an hour, although they may last for up to 24 hours. Because you cannot tell if these symptoms are from a TIA or a stroke, you should go to the hospital right away.

TIAs are often a warning sign for future strokes. Taking medicine, such as blood thinners, may reduce your risk of a stroke. Your doctor might also recommend surgery. You can also help lower your risk by having a healthy lifestyle. This includes not smoking, not drinking too much, eating a healthy diet, and exercising. It is also important to control other health problems, such as high blood pressure and cholesterol.

NIH: National Institute of Neurological Disorders and Stroke

  • Transient ischemic attack (Medical Encyclopedia)
  • Vertebrobasilar circulatory disorders (Medical Encyclopedia)

[Learn More]