2026 ICD-10-CM Diagnosis Code D80.5Immunodeficiency with increased immunoglobulin M [IgM]

ICD-10-CM Codes›D50–D89›D80-D89›D80

ICD-10-CM D80.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D80.5 is a billable ICD-10-CM diagnosis code for immunodeficiency with increased immunoglobulin M [IgM]. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 814 through 816. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Immunity disorders.

Code Identity

ICD-10-CM Code
D80.5
Billable Status
Yes — Valid for Submission
Code Describes
Immunodeficiency with increased immunoglobulin M [IgM]
Short Description
Immunodeficiency with increased immunoglobulin M [IgM]
Same as the full description in the CMS dataset.
Parent Code
D80
Immunodeficiency with predominantly antibody defects

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
CategoryD80Immunodeficiency with predominantly antibody defects
This CodeD80.5Immunodeficiency with increased immunoglobulin M [IgM]

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Autosomal dominant hyperimmunoglobulin M syndrome due to AID deficiency
  • Autosomal recessive hyperimmunoglobulin M syndrome
  • Autosomal recessive hyperimmunoglobulin M syndrome due to AID deficiency
  • Autosomal recessive hyperimmunoglobulin M syndrome due to APRIL deficiency
  • Autosomal recessive hyperimmunoglobulin M syndrome due to CTNNBL1 deficiency
  • Autosomal recessive hyperimmunoglobulin M syndrome due to INO80 deficiency
  • Autosomal recessive hyperimmunoglobulin M syndrome due to MSH6 deficiency
  • Autosomal recessive hyperimmunoglobulin M syndrome due to UNG deficiency
  • Constitutional mismatch repair deficiency syndrome
  • Hyperimmunoglobulin M syndrome
  • Hyperimmunoglobulin M syndrome type 3
  • Hyperimmunoglobulin M syndrome with susceptibility to opportunistic infection
  • Hyperimmunoglobulin M syndrome without susceptibility to opportunistic infection
  • X-linked hyper-IgM syndrome

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Immunodeficiency
      • with
        • increased immunoglobulin M (IgM)
    • Immunodeficiency
      • X-linked, with increased IgM

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR BLD008
Immunity disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

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.

Convert D80.5 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
279.05 Immunodefic w hyper-igm
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About D80.5Overview

Is D80.5 (Immunodeficiency with predominantly antibody defects) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report immunodeficiency with increased immunoglobulin M [IgM] on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does D80.5 group to?

When immunodeficiency with increased immunoglobulin M [IgM] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 814, 815, 816, with relative weights from 0.6320 to 2.1267 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of D80.5?

Under the General Equivalence Mappings, immunodeficiency with increased immunoglobulin M [IgM] converts to ICD-9-CM 279.05 (immunodefic w hyper-igm). The mapping is a direct match.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.