2026 ICD-10-CM Diagnosis Code D89.3Immune reconstitution syndrome

ICD-10-CM Codes›D50–D89›D80-D89›D89

ICD-10-CM D89.3
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D89.3 is a billable ICD-10-CM diagnosis code for immune reconstitution syndrome. 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
D89.3
Billable Status
Yes — Valid for Submission
Code Describes
Immune reconstitution syndrome
Short Description
Immune reconstitution syndrome
Same as the full description in the CMS dataset.
Parent Code
D89
Other disorders involving the immune mechanism, not elsewhere classified

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
CategoryD89Other disorders involving the immune mechanism, not elsewhere classified
This CodeD89.3Immune reconstitution syndrome

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Disorder of immune reconstitution
  • Engraftment reaction
  • Engraftment syndrome
  • Evidence of immune reconstitution
  • Immune reconstitution finding
  • Immune reconstitution inflammatory syndrome
  • Immune reconstitution reaction

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Immune reconstitution inflammatory syndrome IRIS

Use Additional Code

  • code for adverse effect, if applicable, to identify drug T36 T50

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.

    • Immune reconstitution(inflammatory) syndrome [IRIS]
    • Syndrome
      • immune reconstitution
    • Syndrome
      • immune reconstitution inflammatory [IRIS]

Clinical ClassificationClinical

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

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

Clinical InformationClinical

  • Immune Reconstitution Inflammatory Syndrome

    exuberant inflammatory response towards a previously acquired or undiagnosed opportunistic infection. it is frequently seen in aids patients following antiretroviral treatment.

  • Engraftment Syndrome

    a toxicity of hematopoietic stem cell transplantation that manifests as fever, rash and pulmonary deterioration which becomes evident at marrow engraftment. it occurs unexpectedly and is occasionally fatal. it can occur after an autogeneic or an allogeneic hematopoietic cell transplantation.

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 D89.3 to ICD-9-CMHistory

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

ICD-9-CM
279.8 Immune mechanism dis NEC
Approximate The match is approximate rather than exact.

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 D89.3Overview

Is D89.3 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report immune reconstitution syndrome on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does D89.3 group to?

When immune reconstitution syndrome 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 D89.3?

Under the General Equivalence Mappings, immune reconstitution syndrome converts to ICD-9-CM 279.8 (immune mechanism dis NEC). The mapping is approximate, so confirm the match fits the documentation.

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.