Search Browse Crosswalk Fees Tools Pricing

Codelle

AI-powered medical coding assistant for healthcare practices and billers.

Pricing Privacy Terms

© 2026 Codelle. All rights reserved.

CPT® copyright 2026 American Medical Association. All rights reserved. CPT is a registered trademark of the American Medical Association. Applicable FARS/DFARS restrictions apply to government use. Fee schedules, relative value units, conversion factors and/or related components are not assigned by the AMA, are not part of CPT, and the AMA is not recommending their use.

ICD-10-CM D89.4 — Mast cell activation syndrome a… | Codelle

ICD-10-CM/D89/D89.4

D89.4

ICD-10-CM

Mast cell activation syndrome and related disorders

Clinical Notes

Excludes 1 — Not coded here

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)

Code Hierarchy

▲D89Oth disorders involving the immune mechanism, NEC

D89.4(current)

Subcodes (6)

D89.40Mast cell activation, unspecified

D89.41Monoclonal mast cell activation syndrome

D89.42Idiopathic mast cell activation syndrome

D89.43Secondary mast cell activation

D89.44Hereditary alpha tryptasemia

D89.49Other mast cell activation disorder

Same Category

D89Oth disorders involving the immune mechanism, NEC D89.0Polyclonal hypergammaglobulinemia D89.1Cryoglobulinemia D89.2Hypergammaglobulinemia, unspecified D89.3Immune reconstitution syndrome D89.40

Mast cell activation, unspecified

D89.41Monoclonal mast cell activation syndrome

D89.42Idiopathic mast cell activation syndrome

D89.43Secondary mast cell activation

D89.44Hereditary alpha tryptasemia

+5 more in this category