2027 ICD-10-CM Diagnosis Code D81Combined immunodeficiencies

ICD-10-CM Codes›D50–D89›D80-D89›D81

ICD-10-CM D81
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

D81 is a non-billable ICD-10-CM category code for combined immunodeficiencies, so it cannot be submitted on claims. Use a more specific code from this category instead, such as D81.0, D81.1, D81.2, and D81.30.

Code Identity

ICD-10-CM Code
D81
Billable Status
No — Non-Billable Category
Code Describes
Combined immunodeficiencies
Short Description
Combined immunodeficiencies
Same as the full description in the CMS dataset.
Chapter
D80-D89
Certain disorders involving the immune mechanism

Code Classification

ChapterD50–D89Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism
SectionD80-D89Certain disorders involving the immune mechanism
CategoryD81Combined immunodeficiencies
This CodeD81Combined immunodeficiencies

Specific Coding for Combined immunodeficienciesOverview

Non-specific codes like D81 require more characters. Use one of these billable codes instead:

  • Use D81.0 for Severe combined immunodeficiency [SCID] with reticular dysgenesis

  • Use D81.1 for Severe combined immunodeficiency [SCID] with low T- and B-cell numbers

  • Use D81.2 for Severe combined immunodeficiency [SCID] with low or normal B-cell numbers

  • D81.3 for Adenosine deaminase [ADA] deficiency

  • Use D81.30 for Adenosine deaminase deficiency, unspecified

  • Use D81.31 for Severe combined immunodeficiency due to adenosine deaminase deficiency

  • Use D81.32 for Adenosine deaminase 2 deficiency

  • Use D81.39 for Other adenosine deaminase deficiency

  • Use D81.4 for Nezelof's syndrome

  • Use D81.5 for Purine nucleoside phosphorylase [PNP] deficiency

  • Use D81.6 for Major histocompatibility complex class I deficiency

  • Use D81.7 for Major histocompatibility complex class II deficiency

  • D81.8 for Other combined immunodeficiencies

  • D81.81 for Biotin-dependent carboxylase deficiency

  • Use D81.82 for Activated Phosphoinositide 3-kinase Delta Syndrome [APDS]

  • Use D81.89 for Other combined immunodeficiencies

  • Use D81.9 for Combined immunodeficiency, unspecified

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to D81: its own notes plus those printed at block D80-D89 and Chapter 3. A note printed at a category, block or chapter applies to every code under it.

Includes

Further defines, or gives examples of, the content of the category.

From Block D80-D89 Certain disorders involving the immune mechanism applies to 83 codes
  • defects in the complement system
  • immunodeficiency disorders, except human immunodeficiency virus [HIV] disease
  • sarcoidosis

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

On D81 itself
  • autosomal recessive agammaglobulinemia (Swiss type) (D80.0)
From Block D80-D89 Certain disorders involving the immune mechanism applies to 83 codes
  • autoimmune disease (systemic) NOS (M35.9)
  • functional disorders of polymorphonuclear neutrophils (D71-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block D80-D89 Certain disorders involving the immune mechanism applies to 83 codes
  • human immunodeficiency virus [HIV] disease (B20)
From Chapter 3 (D50-D89) Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism applies to 324 codes
  • autoimmune disease (systemic) NOS (M35.9)
  • certain conditions originating in the perinatal period (P00-P96)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • human immunodeficiency virus [HIV] disease (B20)
  • injury, poisoning and certain other consequences of external causes (S00-T88)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name D81, its category, or a range that includes it.

Excludes1 3

These codes carry an Excludes1 note naming D81: they are not reported together with it, unless the two conditions are unrelated.

  • E79 Disorders of purine and pyrimidine metabolism
    combined immunodeficiency disorders (D81.-)
  • D72 Other disorders of white blood cells
    immunity disorders (D80-D89) names D80-D89, which includes this code
  • D84.81 Immunodeficiency due to conditions classified elsewhere
    certain disorders involving the immune mechanism (D80-D83, D84.0, D84.1, D84.9) names D80-D83, which includes this code

Patient EducationClinical

Immune System and Disorders

Your immune system is a complex network of cells, tissues, and organs. Together they help the body fight infections and other diseases.

The full article covers:

  • What is the immune system?
  • What are the parts of the immune system?
  • How does the immune system work?
  • What are the types of immunity?
  • What can go wrong with the immune system?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About D81Overview

What is the ICD-10 code for combined immunodeficiencies?

D81 is the ICD-10-CM category for combined immunodeficiencies, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is D81 (Combined immunodeficiencies) a billable code?

No. This is a category header that groups the codes for combined immunodeficiencies, and headers cannot be submitted on claims. Claims for combined immunodeficiencies need a more specific code from this category, such as D81.0, D81.1, and D81.2.

Can D81 be reported with D80.0?

Not as a rule. The Excludes1 note on D81 lists "autosomal recessive agammaglobulinemia (Swiss type) (D80.0)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).