ICD-10-CM D89.4: Mast cell activation syndrome and related disorders

ICD-10-CM Diagnosis Code (2025)

Official Description for D89.4

Mast cell activation syndrome and related disorders

Coding Notes & Guidelines for D89.4

Excludes1: 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)
Use Additional Code
  • code, if applicable, for:
  • allergy status, other than to drugs and biological substances (Z91.0-)
  • personal history of anaphylaxis (Z87.892)
Inclusion Terms
  • Mast cell activation disorder, unspecified
  • Mast cell activation syndrome, NOS
Inclusion Terms

Secondary mast cell activation syndrome

Inclusion Terms

Other mast cell activation syndrome

Code Also

underlying etiology, if known

Parent Code (Less Specific):

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

About ICD-10-CM Code D89.4 (Mast cell activation syndrome and related disorders)

ICD-10-CM code D89.4 is a billable or specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. The 2025 edition of ICD-10-CM D89.4 became effective on October 1, 2024.

This page provides detailed information about D89.4 - Mast cell activation syndrome and related disorders. It includes common terminology, coding guidelines such as "Includes," "Excludes1," and "Excludes2" notes, and information on required 7th characters. Utilizing this information correctly is essential for accurate medical coding and claims submission for conditions like Mast cell activation syndrome and related disorders.