D89.831 (Cytokine release syndrome, grade 1) compared with R77.1 (Abnormality of globulin), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Not coded here — these two are mutually exclusive.
“hyperglobulinemia NOS (R77.1)”
An Excludes1 note means the two conditions cannot occur together, so the pair should not be reported for the same encounter. The sole exception is when the conditions are documented as unrelated to each other.
Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a
No — do not report together. D89.831 carries an Excludes1 note covering R77.1: “hyperglobulinemia NOS (R77.1)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
| D89.831Cytokine release syndrome, grade 1 | R77.1Abnormality of globulin | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | D50-D89 — Diseases of the Blood and Blood-forming Organs and Certain Disorders Involving the Immune Mechanism (D50-D89) | R00-R99 — Symptoms, Signs and Abnormal Clinical and Laboratory Findings, Not Elsewhere Classified (R00-R99) |
| Definition | Cytokine release syndrome, grade 1 is a billable ICD-10-CM diagnosis code (D89.831). | Abnormality of globulin is a billable ICD-10-CM diagnosis code (R77.1). |
| Includes | defects in the complement system immunodeficiency disorders, except human immunodeficiency virus [HIV] disease sarcoidosis | Hyperglobulinemia NOS |
| Use additional code | code for adverse effect, if applicable, to identify immune checkpoint inhibitors and immunostimulant drugs (T45.AX5) code to identify associated manifestations | — |
| Code first | underlying cause, such as: complications following infusion, transfusion and therapeutic injection (T80.89-) | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources