G45.9 — Transient cerebral ischemic attack, unspecified
G45.9 is a billable, specific ICD-10-CM code for transient cerebral ischemic attack, unspecified. It is valid for submission on a claim.
Inclusion terms
Alternative wordings a physician may use in the chart for this same code.
- Spasm of cerebral artery
- TIA
- Transient cerebral ischemia NOS
Other codes that can never be billed with G45.9
These codes carry an Excludes1 note pointing at G45.9. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading G45.9 alone.
- R29.5Transient paralysis
Risk adjustment
G45.9 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
G45.9 is named in 44 Medicare coverage policies — 44 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A52850Billing and Coding: Cardiac Catheterization and Coronary Angiography
- A52868Billing and Coding: Transesophageal Echocardiography (TEE)
- A52992Billing and Coding: Non-Invasive Cerebrovascular Arterial Studies
- A52992Billing and Coding: Non-Invasive Cerebrovascular Arterial Studies
How G45.9 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to G45.9.
- Angiospasm›cerebral
- Attack, attacks›transient ischemic(TIA)
- Claudication›cerebral(artery)
- Spasm, spastic, spasticity›cerebral(arteries) (vascular)
- Disease, diseased›angiospastic›cerebral
- Ischemia, ischemic›cerebral›intermittent
- Ischemia, ischemic›cerebral›transient
- Spasm, spastic, spasticity›artery›cerebral
Related codes at this level
Codes that share G45. If G45.9 is not quite right, the correct code is usually one of these.
Questions about G45.9
- Is G45.9 a billable ICD-10-CM code?
- Yes. G45.9 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does G45.9 sit in the tabular list?
- Diseases of the nervous system (G00-G99), in the block Episodic and paroxysmal disorders (G40-G47).