ICD-10-CM 2027
ICD-10 code for TIA (transient ischemic attack)
Transient cerebral ischemic attack, unspecified
Confirmed by the official ICD-10-CM index entry “attack, attacks › transient ischemic (tia)”. Page updated September 29, 2026.
About coding TIA
The ICD-10-CM code for TIA (transient ischemic attack) is G45.9 (Transient cerebral ischemic attack, unspecified). The official index lists 6 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on G45.9.
It is also searched as mini-stroke.
Within G45, choose G45.9 (Transient cerebral ischemic attack, unspecified) only when documentation doesn't support a more specific option: Vertebro-basilar artery syndrome (G45.0), carotid artery syndrome (hemispheric) (G45.1), multiple and bilateral precerebral artery syndromes (G45.2), Amaurosis fugax (G45.3), transient global amnesia (G45.4) and other transient cerebral ischemic attacks and related syndromes (G45.8).
As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.
In MS-DRG v44.0, it is part of the grouping logic for DRG 061 (Ischemic Stroke, Precerebral Occlusion or Transient Ischemia with Thrombolytic Agent with MCC, relative weight 2.7211), DRG 062 (Ischemic Stroke, Precerebral Occlusion or Transient Ischemia with Thrombolytic Agent with CC, relative weight 1.7781), DRG 063 (Ischemic Stroke, Precerebral Occlusion or Transient Ischemia with Thrombolytic Agent without CC/MCC, relative weight 1.455) and DRG 069 (Transient Ischemia without Thrombolytic, relative weight 0.7964), in MDC 01 (Diseases and Disorders of the Nervous System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
Related TIA codes
Common questions about TIA ICD-10 codes
What is the ICD-10 code for TIA?
- G45.9 — Transient cerebral ischemic attack, unspecified. More specific codes apply when the documentation supports them: G45.0, G45.1, G45.2, G45.3 and others below.
What is the ICD-10 code for vertebro-basilar artery syndrome?
- G45.0 — Vertebro-basilar artery syndrome.
What is the ICD-10 code for carotid artery syndrome (hemispheric)?
- G45.1 — Carotid artery syndrome (hemispheric).
What is the ICD-10 code for multiple and bilateral precerebral artery syndromes?
- G45.2 — Multiple and bilateral precerebral artery syndromes.
What is the ICD-10 code for amaurosis fugax?
- G45.3 — Amaurosis fugax.
What is the ICD-10 code for transient global amnesia?
- G45.4 — Transient global amnesia.
What is the ICD-10 code for other transient cerebral ischemic attacks and related syndromes?
- G45.8 — Other transient cerebral ischemic attacks and related syndromes.
Is G45.9 billable?
- Yes. G45.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can G45.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict G45.9 as a principal diagnosis.
Is G45.9 a CC or MCC?
- G45.9 is a CC (complication or comorbidity) under MS-DRG v44.0, unless excluded by the principal diagnosis.