D89.9
✓ BillableDisorder involving the immune mechanism, unspecified
Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89)
Also Known As
❌ Excludes1
inheritedRules inherited from parent codes in the hierarchy.
- • hyperglobulinemia NOS (R77.1)
- • monoclonal gammopathy (of undetermined significance) (D47.2)
⚠️ Excludes2
inheritedRules inherited from parent codes.
- • transplant failure and rejection (T86.-)
Clinical Description
ICD-10-CM code D89.9 represents disorder involving the immune mechanism, unspecified. This code falls under the Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89) classification. It is a billable/specific code valid for HIPAA-covered transactions as of October 1, 2025 (FY2026). This code can be used to indicate a diagnosis for reimbursement purposes on insurance claims.
This is a 5-character code at the 4th level of specificity. This is the most specific code available in this subcategory. Coders should note that D89.9 has 2 Excludes1 restriction(s) — codes that cannot be reported together on the same claim.
Frequently Asked Questions
What is ICD-10 code D89.9?
ICD-10-CM code D89.9 is "Disorder involving the immune mechanism, unspecified". It belongs to the category: Diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (D50-D89).
Is D89.9 a billable ICD-10 code?
Yes, D89.9 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
What codes are excluded with D89.9?
D89.9 has 2 Excludes1 rule(s). These codes are mutually exclusive and cannot be coded together on the same claim.
Can D89.9 be coded with other codes?
D89.9 has 1 Excludes2 note(s). These conditions can be coded together if both are documented in the patient record.
Related Codes in D89
Other codes in the same category that may be relevant for differential coding:
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Data Source
CMS ICD-10-CM 2026 Tabular List
Updated October 1, 2025 (FY2026)