ICD-10 Code G92.05 – Immune effector cell-associated neurotoxicity syndrome, grade 5 (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code G92.05 – Immune effector cell-associated neurotoxicity syndrome, grade 5
What it is
G92.05 identifies the most severe grade of immune effector cell-associated neurotoxicity syndrome. Use it when documentation confirms grade 5 neurotoxicity after immune effector cell therapy.
Clinical signs
Clinical features vary; refer to documentation. Grade 5 indicates fatal neurotoxicity, so the record should clearly support death attributed to immune effector cell-associated neurotoxicity syndrome.
When to use this code
Use this code when the clinician documents immune effector cell-associated neurotoxicity syndrome with grade 5 severity. It is appropriate in records tied to CAR-T or similar immune effector cell therapies when the adverse neurologic event is specifically graded as 5.
Make sure the diagnosis is explicitly stated and not inferred from general neurologic decline. If the chart only says encephalopathy, seizure, or altered mental status without the syndrome and grade, check documentation.
Do not use for
Do not use it for lower-grade neurotoxicity, nonspecific encephalopathy, or neurologic symptoms without a documented immune effector cell-related syndrome. Check documentation if the grade is missing.
Coding tip
Assign G92.05 only when both the syndrome and grade 5 are documented; otherwise, query the provider.