ICD-10 Diagnosis Code D89.40

Mast cell activation, unspecified

Diagnosis Code D89.40

ICD-10: D89.40
Short Description: Mast cell activation, unspecified
Long Description: Mast cell activation, unspecified
This is the 2017 version of the ICD-10-CM diagnosis code D89.40

New 2017 ICD-10 Code
D89.40 is new to ICD-10 code set for the FY 2017, effective October 1, 2016.

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)

Information for Medical Professionals

Convert to ICD-9 Additional informationCallout TooltipGeneral Equivalence Map
The ICD-10 and ICD-9 GEMs are used to facilitate linking between the diagnosis codes in ICD-9-CM and the new ICD-10-CM code set. The GEMs are the raw material from which providers, health information vendors and payers can derive specific applied mappings to meet their needs.

Index of Diseases and Injuries
References found for the code D89.40 in the Index of Diseases and Injuries:


Replacement Code Additional informationCallout TooltipReplacement Code
The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2016. This is a new and revised code for the FY 2017 (October 1, 2016-September 30, 2017).

This code replaces the following previously assigned ICD-10 code(s) listed below:
  • D89.89 - Oth disrd involving the immune mechanism, NEC


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