D89.40

D89.40: Mast cell activation, unspecified

Billable / specific codeICD-10-CM

D89.40 is a billable, specific ICD-10-CM code for mast cell activation, unspecified. It is valid for submission on a claim.

Check D89.40 with the rest of the claim: free scrubber

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

Mast cell activation disorder, unspecified
Mast cell activation syndrome, NOS

Excludes1 inherited from the categories above D89.40

A category’s note binds every code beneath it.

Written on D89.4: Mast cell activation syndrome and related disorders

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)

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 D89.40

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.

Medicare coverage

D89.40 is named in 1 Medicare coverage policy: 1 listing it as supporting medical necessity. Which one applies depends on your Medicare contractor.

A57689Billing and Coding: Lab: Flow Cytometry

Alphabetic index entries that lead here

Activation›mast cell(disorder) (syndrome)

Code history

Unchanged in every release from FY2024 to FY2027.