D89.42 - Idiopathic mast cell activation syndrome

Version 2023
ICD-10:D89.42
Short Description:Idiopathic mast cell activation syndrome
Long Description:Idiopathic mast cell activation syndrome
Status: Valid for Submission
Version:ICD-10-CM 2023
Code Classification:
  • Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50–D89)
    • Certain disorders involving the immune mechanism (D80-D89)
      • Oth disorders involving the immune mechanism, NEC (D89)

D89.42 is a billable ICD-10 code used to specify a medical diagnosis of idiopathic mast cell activation syndrome. The code is valid during the fiscal year 2023 from October 01, 2022 through September 30, 2023 for the submission of HIPAA-covered transactions.

Approximate Synonyms

The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

Index to Diseases and Injuries References

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for this diagnosis code are found in the injuries and diseases index:

Replacement Code

D8942 replaces the following previously assigned ICD-10 code(s):

Convert to ICD-9 Code

Source ICD-10 CodeTarget ICD-9 Code
D89.42279.8 - Immune mechanism dis NEC
Approximate Flag - The approximate mapping means there is not an exact match between the ICD-10 and ICD-9 codes and the mapped code is not a precise representation of the original code.

Code History