D89.835 – Cytokine release syndrome, grade 5

ICD-10-CM 2027 diagnosis code · Certain disorders involving the immune mechanism

Billable code

ICD-10-CM code D89.835

Code: D89.835 (claims format: D89835)
Description: Cytokine release syndrome, grade 5
Billable: Yes – valid for HIPAA-covered transactions
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 3. Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89)
Block: D80-D89 Certain disorders involving the immune mechanism
Parent codes: D89 › D89.8 › D89.83

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

D89 – Other disorders involving the immune mechanism, not elsewhere classified

Excludes1 (not coded here):

hyperglobulinemia NOS (R77.1)
monoclonal gammopathy (of undetermined significance) (D47.2)

Excludes2 (not included here):

transplant failure and rejection (T86.-)

D89.83 – Cytokine release syndrome

Code first:

underlying cause, such as:
complications following infusion, transfusion and therapeutic injection (T80.89-)
complications of transplanted organs and tissue (T86.-)

Use additional code:

code for adverse effect, if applicable, to identify immune checkpoint inhibitors and immunostimulant drugs (T45.AX5)
code to identify associated manifestations

Block D80-D89

Includes:

defects in the complement system
immunodeficiency disorders, except human immunodeficiency virus [HIV] disease
sarcoidosis

Excludes1 (not coded here):

autoimmune disease (systemic) NOS (M35.9)
functional disorders of polymorphonuclear neutrophils (D71-)

Excludes2 (not included here):

human immunodeficiency virus [HIV] disease (B20)

Index terms for D89.835

Entries in the ICD-10-CM alphabetic index that lead to this code:

Syndrome, cytokine release, grade 5

Related codes in D89.83

D89.831 – Cytokine release syndrome, grade 1Billable
D89.832 – Cytokine release syndrome, grade 2Billable
D89.833 – Cytokine release syndrome, grade 3Billable
D89.834 – Cytokine release syndrome, grade 4Billable
D89.839 – Cytokine release syndrome, grade unspecifiedBillable

Frequently asked questions

What is ICD-10 code D89.835?

D89.835 is the ICD-10-CM code for cytokine release syndrome, grade 5, in the block D80-D89 (Certain disorders involving the immune mechanism).

Is D89.835 a billable code?

Yes. D89.835 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does D89.835 belong to?

It belongs to category D89 – Other disorders involving the immune mechanism, not elsewhere classified.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.