2026 ICD-10-CM Diagnosis Code T80.419ARh incompatibility with hemolytic transfusion reaction, unspecified, initial encounter
ICD-10-CM Codes›S00–T88›T80-T88›T80
- Billable — Valid for Submission
- CC — Complication or Comorbidity
- 7th Character A — Initial Encounter
- Not Chronic
T80.419A is a billable ICD-10-CM diagnosis code for rh incompatibility with hemolytic transfusion reaction, unspecified, 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
Code Classification
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 T80.419A to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About T80.419AOverview
Is T80.419A a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report rh incompatibility with hemolytic transfusion reaction, unspecified, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in T80.419A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for rh incompatibility with hemolytic transfusion reaction, unspecified, such as an emergency visit or first evaluation.
What MS-DRG does T80.419A group to?
When rh incompatibility with hemolytic transfusion reaction, unspecified, 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 T80.419A a CC or MCC?
CMS lists T80.419A 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 T80.419A?
Under the General Equivalence Mappings, rh incompatibility with hemolytic transfusion reaction, unspecified, initial encounter converts to ICD-9-CM 999.71 (rh incomp/HTR NEC). The mapping is approximate, so confirm the match fits the documentation.
