D89.4
Mast cell activation syndrome and related disorders
- Release
- FY 2027
- Effective
Hierarchy
Where D89.4 sits in the official hierarchy. Each level is the code it is classified under.
- D89 Parent Other disorders involving the immune mechanism, not elsewhere classified
- D89.4 This code Mast cell activation syndrome and related disorders
Official Coding Notes
Reproduced verbatim from the FY 2027 ICD-10-CM files. Notes labelled as inherited are declared on a parent code and apply here too.
Excludes1
aggressive systemic mastocytosis ( C96.21 )
Excludes1
hyperglobulinemia NOS ( R77.1 )
Inherited from D89 — Other disorders involving the immune mechanism, not elsewhere classified
Excludes1
congenital cutaneous mastocytosis ( Q82.2 )
Excludes1
monoclonal gammopathy (of undetermined significance) ( D47.2 )
Inherited from D89 — Other disorders involving the immune mechanism, not elsewhere classified
Excludes1
(non-congenital) cutaneous mastocytosis ( D47.01 )
Excludes1
(indolent) systemic mastocytosis ( D47.02 )
Excludes1
malignant mast cell neoplasm ( C96.2- )
Excludes1
malignant mastocytoma ( C96.29 )
Excludes1
mast cell leukemia ( C94.3- )
Excludes1
mast cell sarcoma ( C96.22 )
Excludes1
mastocytoma NOS ( D47.09 )
Excludes1
other mast cell neoplasms of uncertain behavior ( D47.09 )
Excludes1
systemic mastocytosis associated with a clonal hematologic non-mast cell lineage disease (SM-AHNMD) ( D47.02 )
More Specific Codes
6 codes under D89.4
- D89.40 Mast cell activation, unspecified Billable
- D89.41 Monoclonal mast cell activation syndrome Billable
- D89.42 Idiopathic mast cell activation syndrome Billable
- D89.43 Secondary mast cell activation Billable
- D89.44 Hereditary alpha tryptasemia Billable
- D89.49 Other mast cell activation disorder Billable
Version History
How D89.4 appears in each release imported from the official files, newest first.
-
FY 2027 Effective
CurrentMast cell activation syndrome and related disorders
-
FY 2026 Effective
UnchangedMast cell activation syndrome and related disorders
Related Codes
Other codes under D89
- D89.0 Polyclonal hypergammaglobulinemia Billable
- D89.1 Cryoglobulinemia Billable
- D89.2 Hypergammaglobulinemia, unspecified Billable
- D89.3 Immune reconstitution syndrome Billable
- D89.8 Other specified disorders involving the immune mechanism, not elsewhere classified
- D89.9 Disorder involving the immune mechanism, unspecified Billable
Data Source
Code information on this page is derived from the FY 2027 ICD-10-CM files published by CDC NCHS and CMS.
- Release
- FY 2027
- Effective
- Source file
- icd10cm-code-descriptions-2027.zip
Official ICD-10-CM source files (opens in a new tab)
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