2027 ICD-10-CM Diagnosis Code G45.4Transient global amnesia
ICD-10-CM Codes›G00–G99›G40-G47›G45
- Billable — Valid for Submission
- Chronic Condition
G45.4 is a billable ICD-10-CM diagnosis code for transient global amnesia. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 70 through 72. Coders also document this condition as anterograde amnesia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Transient cerebral ischemia.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Anterograde amnesia
- Retrograde amnesia
- Temporary loss of memory
- Transient global amnesia
Instructional NotesGuidance
Instructions from the official ICD-10-CM Tabular List that apply to G45.4: its own notes plus those printed at G45 and Chapter 6. A note printed at a category, block or chapter applies to every code under it.
Excludes1
Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.
- amnesia NOS (R41.3)
Excludes2
Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may 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)
Source: CMS ICD-10-CM Tabular List. How to read instructional notes.
Referenced in Other NotesGuidance
Instructional notes printed at other codes that name G45.4, its category, or a range that includes it.
Excludes1 2
These codes carry an Excludes1 note naming G45.4: they are not reported together with it, unless the two conditions are unrelated.
Excludes2 2
These codes carry an Excludes2 note naming G45.4: its condition is not part of those codes, and both may be reported when the patient has both.
- Chapter 9 (I00-I99) Diseases of the circulatory systemtransient cerebral ischemic attacks and related syndromes (G45.-) names G45.-, which includes this code
- I63.9 Cerebral infarction, unspecifiedtransient cerebral ischemic attacks and related syndromes (G45.-) names G45.-, which includes this code
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
transient global G45.4
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Clinical InformationClinical
Amnesia, Transient Global
a syndrome characterized by a transient loss of the ability to form new memories. it primarily occurs in middle aged or elderly individuals, and episodes may last from minutes to hours. during the period of amnesia, immediate and recent memory abilities are impaired, but the level of consciousness and ability to perform other intellectual tasks are preserved. the condition is related to bilateral dysfunction of the medial portions of each temporal lobe. complete recovery normally occurs, and recurrences are unusual. (from adams et al., principles of neurology, 6th ed, pp429-30)
Patient EducationClinical
Memory
Every day, you have different experiences and you learn new things. Your brain cannot store all of that information, so it has to decide what is worth remembering. Memory is the process of storing and then remembering this information. There are different types of memory. Short-term memory stores information for a few seconds or minutes.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert G45.4 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About G45.4Overview
What is the ICD-10 code for transient global amnesia?
The ICD-10-CM code for transient global amnesia is G45.4 (sometimes written as G454). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
Is G45.4 (Transient cerebral ischemic attacks and related syndromes) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report transient global amnesia on HIPAA-covered claims from October 1, 2026 through September 30, 2027.
What MS-DRG does G45.4 group to?
When transient global amnesia is the principal diagnosis on an inpatient stay, it groups to MS-DRG 72, 70, 71, with relative weights from 0.7344 to 1.6089 depending on complications. Higher weights mean higher Medicare reimbursement.
Can G45.4 be reported with R41.3?
Not as a rule. The Excludes1 note on G45.4 lists "amnesia NOS (R41.3)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).
What is the ICD-9 equivalent of G45.4?
Under the General Equivalence Mappings, transient global amnesia converts to ICD-9-CM 437.7 (transient global amnesia). The mapping is a direct match.
