Other disorders involving the immune mechanism, not elsewhere classified (D89) ICD-10-CM
The D89 code range covers other disorders involving the immune mechanism, not elsewhere classified with 29 ICD-10-CM diagnosis codes. 24 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Type 1 Excludes
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.
Type 2 Excludes
A type 2 excludes note represents "Not included here". An excludes2 note indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes2 note appears under a code, it is acceptable to use both the code and the excluded code together, when appropriate.
- transplant failure and rejection T86
Codes in the D89 Range 29 codes · 24 billable
- D89 Other disorders involving the immune mechanism, not elsewhere classifiedNon-billable
- D89.0 Polyclonal hypergammaglobulinemia
- D89.1 Cryoglobulinemia
- D89.2 Hypergammaglobulinemia, unspecified
- D89.3 Immune reconstitution syndrome
- D89.4 Mast cell activation syndrome and related disordersNon-billable
- D89.40 Mast cell activation, unspecified
- D89.41 Monoclonal mast cell activation syndrome
- D89.42 Idiopathic mast cell activation syndrome
- D89.43 Secondary mast cell activation
- D89.44 Hereditary alpha tryptasemia
- D89.49 Other mast cell activation disorder
- D89.8 Other specified disorders involving the immune mechanism, not elsewhere classifiedNon-billable
- D89.81 Graft-versus-host diseaseNon-billable
- D89.810 Acute graft-versus-host disease
- D89.811 Chronic graft-versus-host disease
- D89.812 Acute on chronic graft-versus-host disease
- D89.813 Graft-versus-host disease, unspecified
- D89.82 Autoimmune lymphoproliferative syndrome [ALPS]
- D89.83 Cytokine release syndromeNon-billable
- D89.831 Cytokine release syndrome, grade 1
- D89.832 Cytokine release syndrome, grade 2
- D89.833 Cytokine release syndrome, grade 3
- D89.834 Cytokine release syndrome, grade 4
- D89.835 Cytokine release syndrome, grade 5
- D89.839 Cytokine release syndrome, grade unspecified
- D89.84 IgG4-related disease
- D89.89 Other specified disorders involving the immune mechanism, not elsewhere classified
- D89.9 Disorder involving the immune mechanism, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the D89 range.
Acute Graft Versus Host Disease
A syndrome of immunologically mediated tissue damage that may occur following an allogeneic transplant, usually affecting the skin, liver, and GI tract. The onset is usually within one hundred days of transplantation or immunologic manipulation.
Acute on Chronic Graft Versus Host Disease
Sudden decompensation of chronic graft versus host disease.
Autoimmune Lymphoproliferative Syndrome
An autoimmune hematologic disorder characterized by autoimmune hemolytic anemia, thrombocytopenia, lymphadenopathy, hepatomegaly and splenomegaly. Patients are at an increased risk of developing Hodgkin and non-Hodgkin lymphomas.
Chronic Graft Versus Host Disease
A syndrome of immunologically mediated tissue damage that may occur following an allogeneic transplant, and may affect multiple organs with manifestations similar to autoimmune diseases. The onset is usually within three years of transplantation or immunologic manipulation.
Cryoglobulinemia
A condition characterized by the presence of abnormal quantities of CRYOGLOBULINS in the blood. Upon cold exposure, these abnormal proteins precipitate into the microvasculature leading to restricted blood flow in the exposed areas.
Cytokine Release Syndrome
A severe immune reaction characterized by excessive release of CYTOKINES. Symptoms include DYSPNEA; FEVER; HEADACHE; HYPOTENSION; NAUSEA; RASH; TACHYCARDIA; HYPOXIA; HYPERFERRITINEMIA, and MULTIPLE ORGAN FAILURE. It is associated with viral infections, SEPSIS; AUTOIMMUNE DISEASES and a variety of factors used in IMMUNOTHERAPY.
Graft vs Host Disease
The clinical entity characterized by anorexia, diarrhea, loss of hair, leukopenia, thrombocytopenia, growth retardation, and eventual death brought about by the GRAFT VS HOST REACTION.
Hypergammaglobulinemia
An excess of GAMMA-GLOBULINS in the serum due to chronic infections or PARAPROTEINEMIAS.
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.
Immunoglobulin G4-Related Disease
A spectrum of systemic autoimmune diseases in which IMMUNOGLOBULIN G4 plays a pathophysiologic role. It can affect multiple organs in highly variable presentations, characterized by inflammatory lesions composed of IgG4-positive PLASMA CELLS, further infiltrated by T helper cells (T-LYMPHOCYTES, HELPER-INDUCER) when linked to progressive FIBROSIS and eventual organ damage.
Monoclonal Mast Cell Activation Syndrome
A rare immunological disorder characterized by mast cell activation in the absence of cutaneous findings. Bone marrow biopsy shows the presence of monoclonal mast cells that carry the D816V KIT gene mutation and/or express CD25 while not meeting the diagnostic requirements for systemic mastocytosis. Patients may present with recurrent symptoms, including hypotension, flushing, headache, abdominal cramping, nausea, diarrhea, arrhythmias, and bronchoconstriction. Symptoms may be triggered by eating, exertion, environmental conditions, emotional stress, or insect stings, and treatment may include antihistamines.
About the D89 Code Range
These are immune system disorders that do not fit elsewhere in the classification. They include named conditions involving gamma globulins, immune reconstitution, and mast cell activation.
The first subdivisions distinguish polyclonal hypergammaglobulinemia, cryoglobulinemia, unspecified hypergammaglobulinemia, and immune reconstitution syndrome. D89.4 groups mast cell activation disorders. Its subdivisions distinguish monoclonal, idiopathic, secondary, unspecified, and other forms, plus hereditary alpha tryptasemia.
D89.8 groups other specified disorders, including graft-versus-host disease, autoimmune lymphoproliferative syndrome, cytokine release syndrome, and IgG4-related disease. Graft-versus-host disease splits into acute, chronic, acute on chronic, and unspecified forms. Cytokine release syndrome splits by grade or unspecified grade. D89.9 identifies an unspecified immune system disorder.
Questions About This Page
How many billable codes are in the D89 range?
Of the 29 codes in this range, 24 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the D89 range classify?
The range classifies other disorders involving the immune mechanism, not elsewhere classified. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
