ICD-10 · PDGM grouping
D89 Other disorders involving the immune mechanism, not elsewhere classified
All 24 codes in the D89 family, with the PDGM clinical group, comorbidity subgroup and primary-position rule CMS assigns, read from the CMS grouper crosswalk v07.2.26 and the CDC FY2027 code file.
Codes in family
24
Can lead a claim
14
Cannot lead a claim
10
What CMS assigns to D89
14 of the 24 codes group to MMTA - Infectious Disease, Neoplasms, and Blood-Forming Diseases; 10 are assigned no clinical group. Comorbidity subgroups: 6 toward Coagulation Defects and Cytokine Release Syndromes; 3 toward Other Combined Immunodeficiencies and Malnutrition, includes graft-versus-host-disease; 15 are assigned none. 14 of the 24 can lead a claim. CMS attaches a code-first note to 10 of the 24.
- Coagulation Defects and Cytokine Release Syndromes
- Other Combined Immunodeficiencies and Malnutrition, includes graft-versus-host-disease: can award the low comorbidity tier as a secondary diagnosis.
Code first
CMS grouper convention 19, on D89.810, D89.811, D89.812, D89.813, D89.831, D89.832, D89.833, D89.834, D89.835, D89.839. Code first:
- complications of blood transfusion (T80.89)
- complications of transplanted organs and tissue (T86.-)
- underlying cause, such as:
Every code in D89
Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.
| Code | Description | Primary position | Clinical group | Comorbidity subgroup |
|---|---|---|---|---|
| D89.0 | Polyclonal hypergammaglobulinemia | Can lead a claim | K | None |
| D89.1 | Cryoglobulinemia | Can lead a claim | K | None |
| D89.2 | Hypergammaglobulinemia, unspecified | Can lead a claim | K | None |
| D89.3 | Immune reconstitution syndrome | Can lead a claim | K | None |
| D89.4 Mast cell activation syndrome and related disorders | ||||
| D89.40 | Mast cell activation, unspecified | Can lead a claim | K | None |
| D89.41 | Monoclonal mast cell activation syndrome | Can lead a claim | K | None |
| D89.42 | Idiopathic mast cell activation syndrome | Can lead a claim | K | None |
| D89.43 | Secondary mast cell activation | Can lead a claim | K | None |
| D89.44 | Hereditary alpha tryptasemia | Can lead a claim | K | None |
| D89.49 | Other mast cell activation disorder | Can lead a claim | K | None |
| D89.8 Other specified disorders involving the immune mechanism, not elsewhere classified | ||||
| D89.81 Graft-versus-host disease | ||||
| D89.810 | Acute graft-versus-host disease | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | Other Combined Immunodeficiencies and Malnutrition, includes graft-versus-host-disease |
| D89.811 | Chronic graft-versus-host disease | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | Other Combined Immunodeficiencies and Malnutrition, includes graft-versus-host-disease |
| D89.812 | Acute on chronic graft-versus-host disease | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | Other Combined Immunodeficiencies and Malnutrition, includes graft-versus-host-disease |
| D89.813 | Graft-versus-host disease, unspecified | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | None |
| D89.82 | Autoimmune lymphoproliferative syndrome [ALPS] | Can lead a claim | K | None |
| D89.83 Cytokine release syndrome | ||||
| D89.831 | Cytokine release syndrome, grade 1 | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | Coagulation Defects and Cytokine Release Syndromes |
| D89.832 | Cytokine release syndrome, grade 2 | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | Coagulation Defects and Cytokine Release Syndromes |
| D89.833 | Cytokine release syndrome, grade 3 | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | Coagulation Defects and Cytokine Release Syndromes |
| D89.834 | Cytokine release syndrome, grade 4 | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | Coagulation Defects and Cytokine Release Syndromes |
| D89.835 | Cytokine release syndrome, grade 5 | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | Coagulation Defects and Cytokine Release Syndromes |
| D89.839 | Cytokine release syndrome, grade unspecified | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | Coagulation Defects and Cytokine Release Syndromes |
| D89.84 | IgG4-related disease | Can lead a claim | K | None |
| D89.89 | Other specified disorders involving the immune mechanism, not elsewhere classifiedCMS: Oth disrd involving the immune mechanism, NEC | Can lead a claim | K | None |
| D89.9 | Disorder involving the immune mechanism, unspecified | Can lead a claim | K | None |
Sources: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01, for the clinical group, comorbidity subgroup, code-first conventions and primary-position flags; CDC NCHS ICD-10-CM FY2027 code descriptions for the family title and code wording. This is the crosswalk Medicare runs a claim through. Grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list.
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