2026 ICD-10-CM Diagnosis Code T80.911ADelayed hemolytic transfusion reaction, unspecified incompatibility, initial encounter
T80.911A is a billable ICD-10-CM diagnosis code for delayed hemolytic transfusion reaction, unspecified incompatibility, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 811 through 812. Coders also document this condition as anemia caused by alloimmune destruction of transfused red cells. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication of other surgical or medical care, injury, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Anemia caused by alloimmune destruction of transfused red cells
- Delayed hemolytic transfusion reaction
- Hematologic complication of procedure
- Hemolytic transfusion reaction
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Complications following infusion, transfusion and therapeutic injection (T80). Use the following options for the applicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Blood Transfusion and Donation
Every year, millions of people in the United States receive life-saving blood transfusions. During a transfusion, you receive whole blood or parts of blood such as:
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert T80.911A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T80.911AOverview
Is T80.911A a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report delayed hemolytic transfusion reaction, unspecified incompatibility, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T80.911A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for delayed hemolytic transfusion reaction, unspecified incompatibility, such as an emergency visit or first evaluation.
What MS-DRG does T80.911A group to?
When delayed hemolytic transfusion reaction, unspecified incompatibility, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 811, 812, with relative weights from 0.9182 to 1.4043 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of T80.911A?
Under the General Equivalence Mappings, delayed hemolytic transfusion reaction, unspecified incompatibility, initial encounter converts to ICD-9-CM 999.85 (delayed HTR NOS). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
