2022 ICD-10-CM Code G45.9

Transient cerebral ischemic attack, unspecified

Version 2021

Valid for Submission

ICD-10:G45.9
Short Description:Transient cerebral ischemic attack, unspecified
Long Description:Transient cerebral ischemic attack, unspecified

Code Classification

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

G45.9 is a billable diagnosis code used to specify a medical diagnosis of transient cerebral ischemic attack, unspecified. The code G45.9 is valid during the fiscal year 2022 from October 01, 2021 through September 30, 2022 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.

Unspecified diagnosis codes like G45.9 are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

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 coding notes and 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.

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:

Approximate Synonyms

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

Convert G45.9 to ICD-9 Code

The General Equivalency Mapping (GEM) crosswalk indicates an approximate mapping between the ICD-10 code G45.9 its ICD-9 equivalent. The approximate mapping means there is not an exact match between the ICD-10 code and the ICD-9 code and the mapped code is not a precise representation of the original code.

Information for Patients


Transient Ischemic Attack

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

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


[Learn More in MedlinePlus]

Code History

  • 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 (First year ICD-10-CM implemented into the HIPAA code set)