G45.9 — Transient cerebral ischemic attack, unspecified
Is G45.9 billable?
Yes, but G45.9 is an unspecified code. G45.9 is a valid, billable ICD-10-CM code for encounters from October 1, 2026 through September 30, 2027. However, G45.9 is an unspecified or catch-all code. Payers apply additional scrutiny to unspecified codes and many deny them when the medical record supports a more specific option, so check the documentation before selecting G45.9 — the more specific alternatives are listed below.
G45.9 at a glance
| Code | G45.9 |
|---|---|
| Description | Transient cerebral ischemic attack, unspecified |
| Billable | Yes |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Which MS-DRGs does G45.9 group to?
G45.9 sits in MDC 01 and helps define the logic of 3 MS-DRGs (version 44, FY2027). Which one a stay actually groups to also depends on procedures and secondary diagnoses.
- 061Ischemic Stroke, Precerebral Occlusion or Transient Ischemia with Thrombolytic Agent with MCCmedical
- 062Ischemic Stroke, Precerebral Occlusion or Transient Ischemia with Thrombolytic Agent with CCmedical
- 063Ischemic Stroke, Precerebral Occlusion or Transient Ischemia with Thrombolytic Agent without CC/MCCmedical
As a secondary diagnosis, G45.9 is a complication or comorbidity (CC), which can move a stay into a higher-paying DRG.
How is G45.9 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to G45.9. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Angiospasm › cerebral (peripheral) (traumatic) (vessel)
- Attack, attacks › transient ischemic
- Claudication › cerebral (intermittent)
- Spasm, spastic, spasticity › cerebral (s)
- Disease, diseased › angiospastic › cerebral
- Ischemia, ischemic › cerebral › intermittent
- Ischemia, ischemic › cerebral › transient
- Spasm, spastic, spasticity › artery › cerebral (s)
Inclusion terms
Alternative wording in documentation that is classified to G45.9.
- Spasm of cerebral artery
- TIA
- Transient cerebral ischemia NOS
Excludes1 — never code together — inherited from G45
The conditions below can never be reported together with G45.9 on the same claim. An Excludes1 note means the two conditions cannot occur in the same patient, so reporting both is a coding error.
Excludes2 — not included here — inherited from Chapter 6
The conditions below are not part of G45.9, but a patient may have both at the same time. When documentation supports it, G45.9 and the excluded code may both be reported.
- certain conditions originating in the perinatal period (P04-P96)
- certain infectious and parasitic diseases (A00-B99)
- complications of pregnancy, childbirth and the puerperium (O00-O9A)
- congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
- endocrine, nutritional and metabolic diseases (E00-E88)
- injury, poisoning and certain other consequences of external causes (S00-T88)
- neoplasms (C00-D49)
- symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
How long has G45.9 existed?
G45.9 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.
Which codes are confused with G45.9?
ICD-10-CM declares these codes mutually exclusive with G45.9 — exactly one of each pair can be correct for a given encounter.