2021 ICD-10-CM Code D84.1

Defects in the complement system

Version 2021

Valid for Submission

D84.1 is a billable diagnosis code used to specify a medical diagnosis of defects in the complement system. The code D84.1 is valid during the fiscal year 2021 from October 01, 2020 through September 30, 2021 for the submission of HIPAA-covered transactions.

The ICD-10-CM code D84.1 might also be used to specify conditions or terms like acquired angioedema due to c1 inhibitor autoantibody, acquired c1 esterase inhibitor deficiency, alternative pathway deficiency, anaphylotoxin inactivator deficiency, angioedema due to disorder of kinin metabolism , angioedema due to disorder of kinin metabolism, etc.

ICD-10:D84.1
Short Description:Defects in the complement system
Long Description:Defects in the complement system

Code Classification

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 coding notes and guidance for inclusions, exclusions, descriptions and more. The following references are applicable to the code D84.1:


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.

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 D84.1 are found in the index:

Approximate Synonyms

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

Convert D84.1 to ICD-9 Code

The General Equivalency Mapping (GEM) crosswalk indicates an approximate mapping between the ICD-10 code D84.1 its ICD-9 equivalent. The approximate mapping means there is not an exact match between the ICD-10 code and the ICD-9 code and the mapped code is not a precise representation of the original code.

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

NIH: National Institute of Allergy and Infectious Diseases


[Learn More in MedlinePlus]

Complement component 8 deficiency Complement component 8 deficiency is a disorder that causes the immune system to malfunction, resulting in a form of immunodeficiency. Immunodeficiencies are conditions in which the immune system is not able to protect the body effectively from foreign invaders such as bacteria. People with complement component 8 deficiency have a significantly increased risk of recurrent bacterial infections, particularly by a bacterium called Neisseria meningitidis. Infection by this bacterium causes inflammation of the membranes surrounding the brain and spinal cord (meningitis). Although meningitis can be life-threatening, individuals with complement component 8 deficiency are less likely to die from the infection than people in the general population who contract it.The severity of complement component 8 deficiency varies widely. While some people with this condition experience one or more infections, others do not have any health problems related to the disorder.There are two types of complement component 8 deficiency, types I and II, classified by their genetic cause. The two types have the same signs and symptoms.
[Learn More in MedlinePlus]

Code History

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