October 1 update. Our PDGM and ICD-10 tools now use the FY2027 code set: 190 codes added, 30 deleted, and no existing code changed clinical group.

See what changed

ICD-10 · PDGM grouping

D84 Other immunodeficiencies

All 7 codes in the D84 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.

ICD-10-CM FY2027 · CMS grouper v07.2.26

Codes in family

7

Can lead a claim

6

Cannot lead a claim

1

What CMS assigns to D84

6 of the 7 codes group to MMTA - Infectious Disease, Neoplasms, and Blood-Forming Diseases; 1 is assigned no clinical group. None of the 7 is assigned a comorbidity subgroup. 6 of the 7 can lead a claim. CMS attaches a code-first note to 1 of the 7.

Code first

CMS grouper convention 18, on D84.81. Code first:

  • chromosomal abnormalities (Q90-Q99)
  • diabetes mellitus (E08-E13)
  • malignant neoplasms (C00-C96)
  • underlying condition, such as:

Every code in D84

Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.

CodeDescriptionPrimary positionClinical groupComorbidity subgroup
D84.0Lymphocyte function antigen-1 [LFA-1] defectCan lead a claimKNone
D84.1Defects in the complement systemCan lead a claimKNone
D84.8 Other specified immunodeficiencies
D84.81Immunodeficiency due to conditions classified elsewhereCannot lead a claimManifestation code is not reportable as principal diagnosisNoneNone
D84.82 Immunodeficiency due to drugs and external causes
D84.821Immunodeficiency due to drugsCan lead a claimKNone
D84.822Immunodeficiency due to external causesCan lead a claimKNone
D84.89Other immunodeficienciesCan lead a claimKNone
D84.9Immunodeficiency, unspecifiedCan lead a claimKNone

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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