D89 – Other disorders involving the immune mechanism, not elsewhere classified

ICD-10-CM 2027 diagnosis code · Certain disorders involving the immune mechanism

Non-billable header

ICD-10-CM code D89

Code: D89 (claims format: D89)
Description: Other disorders involving the immune mechanism, not elsewhere classified
Short description: Oth disorders involving the immune mechanism, NEC
Billable: No – use a more specific code below
Valid for: Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter: 3. Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89)
Block: D80-D89 Certain disorders involving the immune mechanism

Billable codes under D89

D89 is a header code and cannot be used on claims. Choose the most specific code:

D89.0 – Polyclonal hypergammaglobulinemiaBillable
D89.1 – CryoglobulinemiaBillable
D89.2 – Hypergammaglobulinemia, unspecifiedBillable
D89.3 – Immune reconstitution syndromeBillable
D89.4 – Mast cell activation syndrome and related disordersHeader (more codes below)
D89.8 – Other specified disorders involving the immune mechanism, not elsewhere classifiedHeader (more codes below)
D89.9 – Disorder involving the immune mechanism, unspecifiedBillable

Notes for D89

Excludes1 (not coded here):

hyperglobulinemia NOS (R77.1)
monoclonal gammopathy (of undetermined significance) (D47.2)

Excludes2 (not included here):

transplant failure and rejection (T86.-)

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Block D80-D89

Includes:

defects in the complement system
immunodeficiency disorders, except human immunodeficiency virus [HIV] disease
sarcoidosis

Excludes1 (not coded here):

autoimmune disease (systemic) NOS (M35.9)
functional disorders of polymorphonuclear neutrophils (D71-)

Excludes2 (not included here):

human immunodeficiency virus [HIV] disease (B20)

Frequently asked questions

What is ICD-10 code D89?

D89 is the ICD-10-CM code for other disorders involving the immune mechanism, not elsewhere classified, in the block D80-D89 (Certain disorders involving the immune mechanism).

Is D89 a billable code?

No. D89 is a header code with more specific child codes; report one of the billable codes listed above.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.