ICD-10-CM Codes Browse (Tabular) Diagnostic External Drug Neoplasm

D89.42 – Idiopathic mast cell activation syndrome

Coding Notes

Active

Billable, valid for HIPAA-covered transactions

GEM Conversion to ICD-9 CM

279.8

Fs: 10000 – Other specified disorders involving the immune mechanism

MDC / MS-DRG Reference

DRG 814

RETICULOENDOTHELIAL AND IMMUNITY DISORDERS WITH MCC

DRG 815

RETICULOENDOTHELIAL AND IMMUNITY DISORDERS WITH CC

DRG 816

RETICULOENDOTHELIAL AND IMMUNITY DISORDERS WITHOUT CC/MCC

Back Reference of Diagnostic Codes

Activation

mast cell (disorder) (syndrome) D89.40

idiopathic D89.42

Sibling Codes

D89.40

Mast cell activation, unspecified

D89.41

Monoclonal mast cell activation syndrome

D89.43

Secondary mast cell activation

D89.44

Hereditary alpha tryptasemia

D89.49

Other mast cell activation disorder

Parent Sibling Codes

D89.0

Polyclonal hypergammaglobulinemia

D89.1

Cryoglobulinemia

D89.2

Hypergammaglobulinemia, unspecified

D89.3

Immune reconstitution syndrome

D89.4

Mast cell activation syndrome and related disorders

D89.8

Other specified disorders involving the immune mechanism, not elsewhere classified

D89.9

Disorder involving the immune mechanism, unspecified

View in Tabular

Code	Title
D50-D89	Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89)
D80-D89	Certain disorders involving the immune mechanism (D80-D89)
D89	Other disorders involving the immune mechanism, not elsewhere classified
D89.4	Mast cell activation syndrome and related disorders
D89.42	Idiopathic mast cell activation syndrome