2026 ICD-10-CM Diagnosis Code T80.A9XAOther non-ABO incompatibility reaction due to transfusion of blood or blood products, initial encounter

ICD-10-CM Codes›S00–T88›T80-T88›T80

ICD-10-CM T80.A9XA
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T80.A9XA is a billable ICD-10-CM diagnosis code for other non-ABO incompatibility reaction due to transfusion of blood or blood products, 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 791, 793, 811 through 812. As a secondary diagnosis, it counts as a complication or comorbidity (CC) and moves an inpatient stay to a higher severity level within its MS-DRG family. It does not count, however, when the principal diagnosis is one of 20 closely related codes. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Complication of other surgical or medical care, injury, initial encounter.

Code Identity

ICD-10-CM Code
T80.A9XA
Billable Status
Yes — Valid for Submission
Code Describes
Other non-ABO incompatibility reaction due to transfusion of blood or blood products, initial encounter
Short Description
Oth non-ABO incompat react d/t tranfs of bld/bld prod, init
Parent Code
Other non-ABO incompatibility reaction due to transfusion of blood or blood products

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT80-T88Complications of surgical and medical care, not elsewhere classified
CategoryT80Complications following infusion, transfusion and therapeutic injection
This CodeT80.A9XAOther non-ABO incompatibility reaction due to transfusion of blood or blood products, initial encounter

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.

CCSR INJ037
Complication of other surgical or medical care, injury, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

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.A9XA to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
999.79 Non-abo incomp react NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About T80.A9XAOverview

Is T80.A9XA a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other non-ABO incompatibility reaction due to transfusion of blood or blood products, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in T80.A9XA mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for other non-ABO incompatibility reaction due to transfusion of blood or blood products, such as an emergency visit or first evaluation.

What MS-DRG does T80.A9XA group to?

When other non-ABO incompatibility reaction due to transfusion of blood or blood products, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 791, 793, 811, 812, with relative weights from 0.9182 to 4.1696 depending on complications. Higher weights mean higher Medicare reimbursement.

Is T80.A9XA a CC or MCC?

CMS lists T80.A9XA as a CC (complication or comorbidity) for FY 2026. Reported as a secondary diagnosis, it moves the inpatient stay to a higher-weighted DRG within its severity family. It does not count when the principal diagnosis is one of the 20 closely related codes in its exclusion list.

What is the ICD-9 equivalent of T80.A9XA?

Under the General Equivalence Mappings, other non-ABO incompatibility reaction due to transfusion of blood or blood products, initial encounter converts to ICD-9-CM 999.79 (non-abo incomp react NEC). The mapping is approximate, so confirm the match fits the documentation.