ICD-10-CM Code D89.9

Disorder involving the immune mechanism, unspecified

Version 2021 Billable Code

Valid for Submission

D89.9 is a billable code used to specify a medical diagnosis of disorder involving the immune mechanism, unspecified. The code is valid for the fiscal year 2021 for the submission of HIPAA-covered transactions. The ICD-10-CM code D89.9 might also be used to specify conditions or terms like abnormal host defense, abnormal host response, antibody-mediated activation and inactivation, autoimmune and/or graft reaction, autoimmune reaction, autoimmune state, etc

Short Description:Disorder involving the immune mechanism, unspecified
Long Description:Disorder involving the immune mechanism, unspecified

Tabular List of Diseases and Injuries

The Tabular List of Diseases and Injuries is a list of ICD-10 codes, organized "head to toe" into chapters and sections with guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code D89.9:

Inclusion Terms

Inclusion Terms
These terms are the conditions for which that code is to be used. The terms may be synonyms of the code title, or, in the case of "other specified" codes, the terms are a list of the various conditions assigned to that code. The inclusion terms are not necessarily exhaustive. Additional terms found only in the Alphabetic Index may also be assigned to a code.
  • Immune disease NOS

Index to Diseases and Injuries

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 the code D89.9 are found in the index:


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

  • Abnormal host defense
  • Abnormal host response
  • Antibody-mediated activation and inactivation
  • Autoimmune AND/OR graft reaction
  • Autoimmune reaction
  • Autoimmune state
  • Autoimmune vasculitis
  • Autonomic neuropathy due to disorder of immune function
  • Chronic disease of immune function
  • Chronic disease of immune structure
  • Cryopathy
  • Disorder of immune function
  • Disorder of immune structure
  • Drug-induced autoimmune reaction
  • Epilepsy due to immune disorder
  • Glomerular disorders in blood diseases and disorders involving the immune mechanism
  • Granulocyte abnormality due to immune defect
  • Hereditary disorder of immune system
  • Immune defect
  • Immune system complication of procedure
  • Immune-mediated neuropathy
  • Immunosuppression-related infectious disease
  • Induced autoimmune reaction
  • Microcephaly, hypogammaglobulinemia, abnormal immunity syndrome
  • Nonspecific immune reaction
  • Panniculitis due to immunological disorder
  • Postvaccinal autoimmune reaction
  • Renal tubulo-interstitial disorders in blood diseases and disorders involving the immune mechanism
  • Spondyloenchondrodysplasia
  • Spondyloenchondrodysplasia with immune dysregulation
  • Ulcer of esophagus due to disorder of immune system

Diagnostic Related Groups

The ICD-10 code D89.9 is grouped in the following groups for version MS-DRG V38.0 What are Diagnostic Related Groups?
The Diagnostic Related Groups (DRGs) are a patient classification scheme which provides a means of relating the type of patients a hospital treats. The DRGs divides all possible principal diagnoses into mutually exclusive principal diagnosis areas referred to as Major Diagnostic Categories (MDC).
applicable from 10/01/2020 through 09/30/2021.


Convert D89.9 to ICD-9

  • 279.9 - Immune mechanism dis NOS

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)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021

Information for Patients

Immune System and Disorders

Your immune system is a complex network of cells, tissues, and organs that work together to defend against germs. It helps your body to recognize these "foreign" invaders. Then its job is to keep them out, or if it can't, to find and destroy them.

If your immune system cannot do its job, the results can be serious. Disorders of the immune system include

  • Allergy and asthma - immune responses to substances that are usually not harmful
  • Immune deficiency diseases - disorders in which the immune system is missing one or more of its parts
  • Autoimmune diseases - diseases causing your immune system to attack your own body's cells and tissues by mistake

NIH: National Institute of Allergy and Infectious Diseases

  • Agammaglobulinemia (Medical Encyclopedia)
  • Aging changes in immunity (Medical Encyclopedia)
  • Chronic granulomatous disease (Medical Encyclopedia)
  • Graft-versus-host disease (Medical Encyclopedia)
  • Histiocytosis (Medical Encyclopedia)
  • Hyperimmunoglobulin E syndrome (Medical Encyclopedia)
  • Immune response (Medical Encyclopedia)
  • Immunodeficiency disorders (Medical Encyclopedia)
  • Selective deficiency of IgA (Medical Encyclopedia)

[Learn More]