D89.4

D89.4: Mast cell activation syndrome and related disorders

Non-billable headerICD-10-CM

D89.4 is a non-billable header ICD-10-CM code for mast cell activation syndrome and related disorders. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1: never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

aggressive systemic mastocytosis (C96.21)
congenital cutaneous mastocytosis (Q82.2)
(non-congenital) cutaneous mastocytosis (D47.01)
(indolent) systemic mastocytosis (D47.02)
malignant mast cell neoplasm (C96.2-)
malignant mastocytoma (C96.29)
mast cell leukemia (C94.3-)
mast cell sarcoma (C96.22)
mastocytoma NOS (D47.09)
other mast cell neoplasms of uncertain behavior (D47.09)
systemic mastocytosis associated with a clonal hematologic non-mast cell lineage disease (SM-AHNMD) (D47.02)

Excludes1 inherited from the categories above D89.4

A category’s note binds every code beneath it.

Written on D89: Other disorders involving the immune mechanism, not elsewhere classified

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

Excludes2 inherited from the categories above D89.4

Not part of this code, but both may be coded when both are present.

Written on D89: Other disorders involving the immune mechanism, not elsewhere classified

transplant failure and rejection (T86.-)

Risk adjustment

No CMS-HCC V28 category: this code does not change a RAF score.

Code history

Unchanged in every release from FY2024 to FY2027.

Code to one of these instead D89.4

6 child codes. Green means billable.