ICD-10 Code D89.839 – Cytokine release syndrome, grade unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D89.839 – Cytokine release syndrome, grade unspecified
What it is
D89.839 identifies cytokine release syndrome when the severity grade is not documented. It is used for a systemic inflammatory reaction triggered by immune activation, often after certain therapies.
Clinical signs
Clinical features vary; refer to documentation. Commonly reported findings include fever, hypotension, tachycardia, hypoxia, and organ dysfunction, but the grade must be stated or clearly implied in the record.
When to use this code
Use D89.839 when the provider documents cytokine release syndrome without specifying a grade. It also fits cases where the record confirms CRS but does not identify severity. If the note includes a specific grade, code that documented grade instead.
Do not use for
Do not use this code for unrelated sepsis, infusion reactions, or other inflammatory syndromes unless the provider specifically documents cytokine release syndrome. Check documentation if the condition is described only as a suspected adverse reaction.
Coding tip
If the grade is missing, code only the documented CRS and query when severity is clinically relevant or expected to be reported.