FY2027 ICD-10-CM reference
D89: Other disorders involving the immune mechanism, not elsewhere classified
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Other disorders involving the immune mechanism, not elsewhere classified. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Nonbillable heading. Verified against the official FY2027 order file.
More specific FY2027 codes
- D89.0: Polyclonal hypergammaglobulinemiaBillable code
- D89.1: CryoglobulinemiaBillable code
- D89.2: Hypergammaglobulinemia, unspecifiedBillable code
- D89.3: Immune reconstitution syndromeBillable code
- D89.4: Mast cell activation syndrome and related disordersNonbillable heading
- D89.8: Other specified disorders involving the immune mechanism, not elsewhere classifiedNonbillable heading
- D89.9: Disorder involving the immune mechanism, unspecifiedBillable code
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Excludes2
autoimmune disease (systemic) NOS (M35.9)
Source: D50-D89 (chapter, inherited).
Excludes2
certain conditions originating in the perinatal period (P00-P96)
Source: D50-D89 (chapter, inherited).
Excludes2
complications of pregnancy, childbirth and the puerperium (O00-O9A)
Source: D50-D89 (chapter, inherited).
Excludes2
congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
Source: D50-D89 (chapter, inherited).
Excludes2
endocrine, nutritional and metabolic diseases (E00-E88)
Source: D50-D89 (chapter, inherited).
Excludes2
human immunodeficiency virus [HIV] disease (B20)
Source: D50-D89 (chapter, inherited).
Excludes2
injury, poisoning and certain other consequences of external causes (S00-T88)
Source: D50-D89 (chapter, inherited).
Excludes2
neoplasms (C00-D49)
Source: D50-D89 (chapter, inherited).
Excludes2
symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
Source: D50-D89 (chapter, inherited).
Includes
defects in the complement system
Source: D80-D89 (section, inherited).
Includes
immunodeficiency disorders, except human immunodeficiency virus [HIV] disease
Source: D80-D89 (section, inherited).
Includes
sarcoidosis
Source: D80-D89 (section, inherited).
Excludes1
autoimmune disease (systemic) NOS (M35.9)
Source: D80-D89 (section, inherited).
Excludes1
functional disorders of polymorphonuclear neutrophils (D71-)
Source: D80-D89 (section, inherited).
Excludes2
human immunodeficiency virus [HIV] disease (B20)
Source: D80-D89 (section, inherited).
Excludes1
hyperglobulinemia NOS (R77.1)
Source: D89 (category, direct).
Excludes1
monoclonal gammopathy (of undetermined significance) (D47.2)
Source: D89 (category, direct).
Excludes2
transplant failure and rejection (T86.-)
Source: D89 (category, direct).
Compare the FY2027 additions, removals and billable-status changes
What does D89 mean in FY2027?
The official ICD-10-CM descriptor is Other disorders involving the immune mechanism, not elsewhere classified. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is D89 billable in FY2027?
The FY2027 order file marks D89 as a nonbillable heading. Select a complete billable child code.
Does D89 map to an HCC?
Risk-model mapping is not applicable to this nonbillable heading. Check a complete billable child code.
Source: CMS FY2027 ICD-10-CM order file. Payment model: CMS CY 2027 Rate Announcement. Read the FY2027 Official Guidelines.
Review the FY2026 April edition