2027 ICD-10-CM Diagnosis Code G92.03Immune effector cell-associated neurotoxicity syndrome, grade 3

ICD-10-CM Codes›G00–G99›G89-G99›G92

ICD-10-CM G92.03
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

G92.03 is a billable ICD-10-CM diagnosis code for immune effector cell-associated neurotoxicity syndrome, grade 3. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 23 through 24, 91 through 93, 791, 793. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 52 closely related codes. The code is not accepted as a principal diagnosis by the Medicare Code Editor. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Drug induced or toxic related condition and Other nervous system disorders (neither hereditary nor degenerative).

Code Identity

ICD-10-CM Code
G92.03
Billable Status
Yes — Valid for Submission
Code Describes
Immune effector cell-associated neurotoxicity syndrome, grade 3
Short Description
Immune effector cell-associated neurotoxicity synd, grade 3
Parent Code
G92.0
Immune effector cell-associated neurotoxicity syndrome

Code Classification

ChapterG00–G99Diseases of the nervous system
SectionG89-G99Other disorders of the nervous system
CategoryG92Toxic encephalopathy
This CodeG92.03Immune effector cell-associated neurotoxicity syndrome, grade 3

Code EditsBilling

Medicare Code Editor checks that affect claim validity for G92.03.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to G92.03: its own notes plus those printed at G92.0 and Chapter 6. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • ICANS, grade 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.

From Chapter 6 (G00-G99) Diseases of the nervous system applies to 700 codes
  • 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)

Code First

The underlying condition named in the note is sequenced before this code.

From G92.0 Immune effector cell-associated neurotoxicity syndrome applies to 6 codes
  • underlying cause such as:
  • complications of immune effector cellular therapy (T80.82)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From G92.0 Immune effector cell-associated neurotoxicity syndrome applies to 6 codes
  • if applicable, associated signs and symptoms, such as:
  • cerebral edema (G93.6)
  • unspecified convulsions (R56.9)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name G92.03, its category, or a range that includes it.

Use Additional Code 2

These codes say to use an additional code from the note, and G92.03 is one of the codes named.

  • G90.81 Serotonin syndrome
    toxic encephalopathy (G92.-) names G92.-, which includes this code
  • T80.82 Complication of immune effector cellular therapy
    immune effector cell-associated neurotoxicity syndrome (G92.0-) names G92.0-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ030
Drug induced or toxic related condition
Default principal diagnosis: inpatient No · outpatient No
CCSR NVS020
Other nervous system disorders (neither hereditary nor degenerative)
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Immune Effector Cell Associated Neurotoxicity Syndrome Grade 3

    immune effector cell-associated neurotoxicity syndrome (icans) characterized by an immune-effector cell-associated encephalopathy (ice) tool score of 0, 1, or 2 (for adults and children over 12), or a cornell assessment of pediatric delirium (capd) score of greater than or equal to 9 (for children 12 and under), the ability of the affected individual to awaken only to tactile stimulus, clinical focal or generalized seizures that resolve rapidly, or non-convulsive seizures detected by electroencephalography (eeg) that resolve with intervention, and local cerebral edema evident on neuroimaging.

Code History & ChangesHistory

Replacement G92.03 replaces the following previously assigned code(s):

  • G92 - Toxic encephalopathy
FY 2022AddedAdded to the ICD-10-CM code setEffective October 1, 2021.
FY 2023–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About G92.03Overview

What is the ICD-10 code for immune effector cell-associated neurotoxicity syndrome, grade 3?

The ICD-10-CM code for immune effector cell-associated neurotoxicity syndrome, grade 3 is G92.03 (sometimes written as G9203). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is G92.03 (Immune effector cell-associated neurotoxicity syndrome) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report immune effector cell-associated neurotoxicity syndrome, grade 3 on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does G92.03 group to?

On inpatient claims, immune effector cell-associated neurotoxicity syndrome, grade 3 maps to MS-DRG 793, 791, 24, 23, 91, 92, 93, with relative weights from 0.7783 to 5.7422 depending on complications. Higher weights mean higher Medicare reimbursement.

Is G92.03 a CC or MCC?

CMS lists G92.03 as a CC (complication or comorbidity) for FY 2027. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 52 closely related codes in its exclusion list.

Can G92.03 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because immune effector cell-associated neurotoxicity syndrome, grade 3 describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.