2026 ICD-10-CM Diagnosis Code D89.89Other specified disorders involving the immune mechanism, not elsewhere classified
ICD-10-CM Codes›D50–D89›D80-D89›D89
- Billable — Valid for Submission
- Chronic Condition
D89.89 is a billable ICD-10-CM diagnosis code for other specified disorders involving the immune mechanism, not elsewhere classified. 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.
D89.89 no longer risk-adjusts for Medicare Advantage: it mapped to HCC 47 under the retired CMS-HCC V24 model through payment year 2025 but maps to no category in the live V28 model. It still risk-adjusts in the PACE (CMS-HCC V22) category 47, ESRD (V21) category 47, ESRD (V24) category 47, and RxHCC Part D (V08) category 99 for payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
D89.89 no longer risk-adjusts for Medicare Advantage: it maps to no payment category in the live CMS-HCC V28 model, although it still risk-adjusts in the other CMS models shown below.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Anti-human leukocyte antigen hyperimmunization
- Autoimmune disorder of bilateral inner ears
- Autoimmune disorder of inner ear
- Autoimmune disorder of left inner ear
- Autoimmune disorder of right inner ear
- Autoimmune enteropathy
- Autoimmune enteropathy and endocrinopathy with susceptibility to chronic infection syndrome
- Autoimmune reaction following infectious disease
- Autoimmune reaction mediated by antibody to tissue element with complement
- Autoimmune reaction mediated by antibody to tissue element without complement
- Autoimmune reaction mediated by B cells
- Autoimmune reaction mediated by cell-mediated immunity
- Autoimmune reaction mediated by immune complex
- Autoimmune reaction mediated by T cells
- Autoimmune reaction, specific organ or cell type
- Autoimmune state
- Autoleukocyte sensitivity
- Autologous state
- Autosensitivity
- BCG granuloma
- Diffuse antibody band pattern
- Disorder of immunoglobulin
- Familial immunoglobulin hypercatabolism
- Hyperimmune state
- Immune dysregulation, inflammatory bowel disease, arthritis, recurrent infection syndrome
- Immunoglobulin hypercatabolism
- Immunologic patching
- Impaired phagocytosis
- Infection caused by Mycobacterium bovis
- Inflammatory disorder of immune system
- Isoimmunization
- Labyrinthitis of bilateral inner ears
- Labyrinthitis of left inner ear
- Labyrinthitis of right inner ear
- Low immunologic affinity
- Nakajo-Nishimura syndrome
- Non-pyogenic bacterial infection of skin
- Pernicious anemia
- Pernicious anemia due to autoimmune disorder
- Primary immunoglobulin catabolism abnormality
- Restricted antibody band pattern
- Reticuloendothelial blockade
- Tuftsin deficiency
- X-linked immune dysregulation, polyendocrinopathy, enteropathy syndrome
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Type 1 Excludes
- human immunodeficiency virus disease B20
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
Disorder (of) See Also: Disease;
autoimmune D89.89
immune mechanism (immunity) D89.9
specified type NEC D89.89
Syndrome See Also: Disease;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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 D89.89 to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About D89.89Overview
Is D89.89 a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other specified disorders involving the immune mechanism, not elsewhere classified on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does D89.89 group to?
When other specified disorders involving the immune mechanism, not elsewhere classified 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 D89.89?
Under the General Equivalence Mappings, other specified disorders involving the immune mechanism, not elsewhere classified converts to ICD-9-CM 279.8 (immune mechanism dis NEC). The mapping is approximate, so confirm the match fits the documentation.
Does D89.89 risk-adjust for Medicare Advantage payment?
Not for Medicare Advantage. D89.89 mapped to HCC 47 in the retired CMS-HCC V24 model, which last determined payment in 2025, but it maps to no category in the live V28 model; see all codes that no longer risk-adjust. It still risk-adjusts in the PACE (CMS-HCC V22) category 47 (Disorders of Immunity), ESRD (V21) category 47 (Disorders of Immunity), ESRD (V24) category 47 (Disorders of Immunity), and RxHCC Part D (V08) category 99 (Immune Disorders).
