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 2026, 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.
Autoimmune Hypophysitis
Immune-mediated inflammation of the PITUITARY GLAND often associated with other autoimmune diseases (e.g., HASHIMOTO DISEASE; GRAVES DISEASE; and ADDISON DISEASE).
Autoimmune Lymphoproliferative Syndrome
Rare congenital lymphoid disorder due to mutations in certain Fas-Fas ligand pathway genes. Known causes include mutations in FAS, TNFSF6, NRAS, CASP8, and CASP10 proteins. Clinical features include LYMPHADENOPATHY; SPLENOMEGALY; and AUTOIMMUNITY.
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.
Cryoglobulins
Abnormal immunoglobulins, especially IGG or IGM, that precipitate spontaneously when SERUM is cooled below 37 degrees Celsius. It is characteristic of CRYOGLOBULINEMIA.
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.
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.
Keratoconjunctivitis Sicca
Drying and inflammation of the conjunctiva as a result of insufficient lacrimal secretion. When found in association with XEROSTOMIA and polyarthritis, it is called SJOGREN'S SYNDROME.
Mast Cell Activation Syndrome
A clinically and genetically heterogeneous group of mast cell disorders in which there is aberrant release of mast cell mediators with little to no accompanying proliferation of MAST CELLS.
Mast Cells
Granulated cells that are found in almost all tissues, most abundantly in the skin and the gastrointestinal tract. Like the BASOPHILS, mast cells contain large amounts of HISTAMINE and HEPARIN. Unlike basophils, mast cells normally remain in the tissues and do not circulate in the blood. Mast cells, derived from the bone marrow stem cells, are regulated by the STEM CELL FACTOR.
About the D89 Code Range
D89 codes cover a range of rare or complex immune system disorders not classified elsewhere. These include hypergammaglobulinemia, cryoglobulinemia, mast cell activation syndromes, graft-versus-host disease, autoimmune lymphoproliferative syndrome, cytokine release syndrome, and IgG4-related disease, among others.
The ICD-10 code for polyclonal hypergammaglobulinemia (D89.0) relates to increased levels of immunoglobulins in the blood, sometimes called Waldenstrom's hypergammaglobulinemic purpura. Codes like D89.1 for cryoglobulinemia address immune complexes that precipitate in cold temperatures, linked to conditions such as vasculitis or hepatitis C. Mast cell activation disorders (D89.4 series) identify abnormal mast cell responses, including mast cell activation syndrome and hereditary alpha tryptasemia. The graft-versus-host disease category (D89.81x) captures immune complications after stem cell or organ transplants, distinguishing between acute, chronic, and unspecified forms with related synonyms to clarify documentation. Other codes like D89.82 for autoimmune lymphoproliferative syndrome and D89.83 for cytokine release syndrome highlight specific immune dysregulation conditions. Thus, the D89 series provides medical coders and clinicians a precise toolset for coding diverse immune mechanism disorders that require careful differentiation for accurate clinical and billing records.
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, 2025 through September 30, 2026. 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 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
