ICD-10-CM 2027
ICD-10 code for Cytokine release syndrome
From the official ICD-10-CM alphabetic index entry “Syndrome › cytokine release”. Page updated September 29, 2026.
About coding Cytokine release syndrome
The ICD-10-CM code for Cytokine release syndrome is D89.839 (Cytokine release syndrome, grade unspecified). The official index lists 5 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on D89.839.
Within D89.83, choose D89.839 (grade unspecified) only when documentation doesn't support a more specific option: grade 1 (D89.831), grade 2 (D89.832), grade 3 (D89.833), grade 4 (D89.834) and grade 5 (D89.835).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 814 (Reticuloendothelial and Immunity Disorders with MCC, relative weight 2.0729), DRG 815 (Reticuloendothelial and Immunity Disorders with CC, relative weight 1.0444) and DRG 816 (Reticuloendothelial and Immunity Disorders without CC/MCC, relative weight 0.7381), in MDC 16 (Diseases and Disorders of the Blood and Blood Forming Organs and Immunological Disorders), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific Cytokine release syndrome codes (official index)
Common questions about Cytokine release syndrome ICD-10 codes
What is the ICD-10 code for Cytokine release syndrome?
- D89.839 — Cytokine release syndrome, grade unspecified. More specific codes apply when the documentation supports them: D89.831, D89.832, D89.833, D89.834 and others below.
What is the ICD-10 code for grade 1 cytokine release syndrome?
- D89.831 — Cytokine release syndrome, grade 1.
What is the ICD-10 code for grade 2 cytokine release syndrome?
- D89.832 — Cytokine release syndrome, grade 2.
What is the ICD-10 code for grade 3 cytokine release syndrome?
- D89.833 — Cytokine release syndrome, grade 3.
What is the ICD-10 code for grade 4 cytokine release syndrome?
- D89.834 — Cytokine release syndrome, grade 4.
What is the ICD-10 code for grade 5 cytokine release syndrome?
- D89.835 — Cytokine release syndrome, grade 5.
Is D89.839 billable?
- Yes. D89.839 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can D89.839 be used as a principal diagnosis?
- No. It is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.
Is D89.839 a CC or MCC?
- No. D89.839 is neither a CC nor an MCC under MS-DRG v44.0.