T80.919A ICD-10-CM Code: Hemolytic transfusion reaction, unspecified incompatibility, unspecified as acute or delayed, initial encounter

Coding instructions

Official Tabular Instructional Notes: the inclusion, exclusion and sequencing notes published for T80.919A in the official ICD-10-CM tabular list, quoted as published.

Notes without a marker are published on T80.919A itself; “inherited from” names the category or block whose note applies here.

7th Character Guide

"The appropriate 7th character is to be added to each code from category T80"

• A — initial encounter (this page’s code)
• D — subsequent encounter
• S — sequela

How the encounter character is assigned. “Initial encounter” means the patient is receiving active treatment for the condition — it is not limited to the first visit, and a different or new provider giving active treatment still assigns it. “Subsequent encounter” covers care during the healing or recovery phase after active treatment. “Sequela” is for complications or conditions that arise as a direct result of the original condition.

ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19.a (paraphrased by MedCoder).

Variant codes in this family

T80.919A, T80.919D, T80.919S

Character meanings are CMS's official 7th-character extensions for this family, as carried in each variant code's official description; variant codes are registry rows. The explanation of how the encounter character is assigned is MedCoder editorial, distinct from the official content above it.

Coder workflow for T80.919A

MedCoder structured workflow — derived from this code’s own official record

Before you code T80.919A

1. Unspecified does not mean incorrect. When the record gives no greater specificity, T80.919A may be the appropriate code. Check the record for detail that supports a more specific sibling — in this subcategory the siblings differ by acute versus chronic. An unspecified code is for records that do not provide the detail a more specific code needs; a query, not an assumption, is the route to specificity (Guidelines I.A.9.b, I.B.18).

   See the relationships section · Guide: Other vs unspecified (NEC vs NOS) →

2. A 7th character is required in this family. Confirm the documented encounter: initial (active treatment), subsequent (healing or recovery phase), or sequela. This page’s code carries “A”. “Initial” means active treatment, not the first visit (Guidelines I.C.19.a).

   See the 7th Character Guide · Guide: 7th characters: initial, subsequent, sequela →

3. Check the Excludes1 note: if the documentation supports a condition named there, do not simply proceed with T80.919A. Excludes1 conditions are not reported together with this code unless the record shows they are unrelated (Guidelines I.A.12.a).

   See the official tabular notes

Choose the right path

1. Does the record document the detail a more specific sibling code needs?
   Yes → Review the specific siblings in this subcategory.
   No → Continue — T80.919A is appropriate when the documentation goes no further.
2. Does the documentation support a condition named in T80.919A’s Excludes1 note?
   Yes → Do not simply proceed: review the excluded code. Both are reported only when the record shows the two conditions are unrelated.
   No → Continue.

   ReviewT80.31, T80.A1, T80.41

3. Is the encounter phase documented — active treatment, healing or recovery, or a sequela?
   Yes → Assign the matching 7th character; the variant codes are in the 7th Character Guide.
   No → The code is invalid without its 7th character — query for the missing element.

Consider T80.919A. Then work the Use Additional Code note, and confirm the code is valid for the date of service in the Verify section.

Documentation check

The provider’s diagnostic statement

Codes are assigned from the provider’s documented diagnosis, not from clinical criteria, test values or a medication list (Guidelines I.A.19).

Encounter type

Active treatment, healing or recovery phase, or sequela — the basis of the 7th character (Guidelines I.C.19.a).

Acuity

Acute or chronic as documented; when both are documented and separate codes exist, both are reported with the acute code first (Guidelines I.B.8).

The conditions the Use Additional Code note names

Reported with this code when documented; a conditional instruction (“if applicable”, “if known”) applies only when the record supports it.

Any detail beyond this code’s title

What the record states that a more specific sibling code would capture — or its absence, which itself supports the unspecified code.

Official instructions as workflow

• Excludes1 — check before selecting T80.919A(3 notes)

  Coding workflow: If the documentation supports a condition named in this note, do not simply proceed with T80.919A: the two are not reported together. The one exception is when the record shows the two conditions are unrelated to each other.

  CompareT80.31, T80.A1, T80.41

  See the official tabular notes · Guidelines I.A.12.a

• Excludes2 — not part of T80.919A(28 notes)

  Coding workflow: The conditions named in this note are not included in T80.919A. When the record documents both, both may be reported; the note is a boundary, not a prohibition.

  CompareT86.01, R50.84, E87.71, D69.51, E83.111, J95.84

  See the official tabular notes · Guidelines I.A.12.b

• Use Additional Code — after identifying T80.919A(3 notes)

  Coding workflow: Check whether the documentation supports the additional code(s) the note names, and report them with T80.919A when it does. Where the instruction is conditional (“if applicable”, “if known”), it applies only when the record documents the condition.

  See the official tabular notes · Guidelines I.A.13

Coding decision scenarios

Pattern scenarios for this code’s structure — decision rules, not clinical cases

Every row is derived from this code’s own record — its title, tabular notes, 7th-character family and same-category siblings — with fixed MedCoder wording; nothing is inferred about a patient. The official notes and guideline text are in the sections each row links to, and they control.

Indexed Clinical Terms (2)

Official source data — entries quoted as published, in the Index’s own lookup phrasing

Clinical term phrases from the official ICD-10-CM Index to Diseases and Injuries that map to this code. These are alphabetic-index entries shown as the Index writes them — lookup phrasing, not necessarily the wording of a final diagnosis.

• Complication (s) (from) (of), transfusion (blood) (lymphocytes) (plasma), hemolytic reaction (antigen unspecified)
• Complication (s) (from) (of), transfusion (blood) (lymphocytes) (plasma), incompatibility reaction (antigen unspecified)

Don’t confuse T80.919A with…

MedCoder analysis — pairs from this code’s official notes, distinctions written by MedCoder

The codes most likely to be picked instead of T80.919A — named in its own official notes, or sharing its laterality or encounter family — with what separates them and which documentation moves the case. Each links to the full comparison.

• T80.31— Excludes1 conflict (Conflict)

  Not coded here — these two are mutually exclusive.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of ABO incompatibility with hemolytic transfusion reaction moves the case to T80.31; the two are not reported together unless documented as unrelated.

  Full comparison: T80.919A vs T80.31 →

• T80.A1— Excludes1 conflict (Conflict)

  Not coded here — these two are mutually exclusive.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of Non-ABO incompatibility with hemolytic transfusion reaction moves the case to T80.A1; the two are not reported together unless documented as unrelated.

  Full comparison: T80.919A vs T80.A1 →

• T80.41— Excludes1 conflict (Conflict)

  Not coded here — these two are mutually exclusive.

  Not reported together with this code, except where the two conditions are documented as unrelated.

  What moves you there: Documentation of Rh incompatibility with hemolytic transfusion reaction moves the case to T80.41; the two are not reported together unless documented as unrelated.

  Full comparison: T80.919A vs T80.41 →

• T80.919D— Encounter relationship (Review)

  Same underlying diagnosis, different encounter phase.

  The same diagnosis at a different phase of care; one encounter takes one 7th character.

  What moves you there: Documentation of a subsequent encounter moves the case to T80.919D.

  Full comparison: T80.919A vs T80.919D →

• T80.919S— Encounter relationship (Review)

  Same underlying diagnosis, different encounter phase.

  The same diagnosis at a different phase of care; one encounter takes one 7th character.

  What moves you there: Documentation of a sequela moves the case to T80.919S.

  Full comparison: T80.919A vs T80.919S →

• T86.01— Excludes2 relationship (Informational)

  Distinct conditions — both may be reported.

  A distinct condition — both may be reported when both are documented.

  What moves you there: Documentation of bone marrow transplant rejection adds T86.01; it is not part of this code and both may be reported when both are documented.

  Full comparison: T80.919A vs T86.01 →

Relationships are read from this code's own official notes, its laterality siblings and its encounter family; the wording of each distinction is MedCoder editorial, and the documentation named in each “what moves you there” line is the official note phrase or sibling title itself. Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a.

Decision Points

The directives on this code's own record, as a pre-claim checklist.

1. A 7th character applies in this family. Confirm the documented encounter matches the character assigned. See the official 7th-character definitions and this code’s variants
2. 3 Use Additional Code instructions — report the named additional code(s) when the documentation supports them. See the Use Additional Code notes
3. 3 Excludes1 entries — codes named there are generally not reported together with this code (Guidelines I.A.12.a). See the Excludes1 notes
4. 28 Excludes2 entries — those conditions are not part of this code and may be reported additionally when documented. See the Excludes2 notes

Checklist rows are derived from this code's own official directives; the wording of each check is MedCoder editorial. The official notes themselves are in the sections each row links to.

Verify Before Coding

• CC as a secondary diagnosis (FY2026). Can raise the stay's MS-DRG severity tier.

From the code registry, the Medicare Code Editor, and the MS-DRG Definitions Manual. Check it against a full claim in Claim Check.

Relationships & Classification

MedCoder structured relationships — computed from published CMS and AHRQ datasets

Other codes that name T80.919A or its code family, from the CMS ICD-10-CM tabular instructional notes. Tabular-note edges are stored at the code family level that carries each note.

Referenced by 1 Excludes1 note: T88.7 — Unspecified adverse effect of drug or medicament (via T80.-).

These codes’ tabular lists mark this diagnosis as mutually exclusive — not reported together unless the conditions are documented as unrelated.

Referenced by 5 Excludes2 notes: T45.8 — Poisoning by, adverse effect of and underdosing of other primarily systemic and hematological agents (via T80.-), T78 — Adverse effects, not elsewhere classified (via T80.-), T79 — Certain early complications of trauma, not elsewhere classified (via T80.-), T81 — Complications of procedures, not elsewhere classified (via T80.-), T88 — Other complications of surgical and medical care, not elsewhere classified (via T80.-).

These codes’ tabular lists name this diagnosis as distinct — both may be reported when both are documented.

MS-DRG Grouper Relationships (FY2026)

Potential MS-DRG participation — not a DRG assignment.

CC — Complication or Comorbidity. Reported as a secondary diagnosis, this code raises the stay's MS-DRG severity tier — except when the principal diagnosis is one of 20 clinically related codes on its CMS exclusion list.

Named in the grouper logic of 4 MS-DRGs: DRG 791 (MDC 15), DRG 793 (MDC 15), DRG 811 (MDC 16), DRG 812 (MDC 16).

From the CMS MS-DRG Definitions Manual (Appendices B and C). Actual DRG assignment depends on the complete claim.

Clinical classification (AHRQ CCSR):INJ037 — Complication of other surgical or medical care, injury, initial encounter (default).

Clinical Classifications Software Refined (CCSR) for ICD-10-CM Diagnoses. Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

Related Codes

Same clinical process (MS-DRG)

Acts as CC — raises the severity of other admissions. CMS groups these diagnoses into one MS-DRG principal-diagnosis exclusion process — a CC/MCC on this list never raises severity when the principal diagnosis is also on it.

J95.87 — Transfusion-associated dyspnea (TAD), T80.30XA — ABO incompatibility reaction due to transfusion of blood or blood products, unspecified, initial encounter, T80.310A — ABO incompatibility with acute hemolytic transfusion reaction, initial encounter, T80.311A — ABO incompatibility with delayed hemolytic transfusion reaction, initial encounter, T80.319A — ABO incompatibility with hemolytic transfusion reaction, unspecified, initial encounter, T80.39XA — Other ABO incompatibility reaction due to transfusion of blood or blood products, initial encounter, T80.40XA — Rh incompatibility reaction due to transfusion of blood or blood products, unspecified, initial encounter, T80.410A — Rh incompatibility with acute hemolytic transfusion reaction, initial encounter, T80.411A — Rh incompatibility with delayed hemolytic transfusion reaction, initial encounter, T80.419A — Rh incompatibility with hemolytic transfusion reaction, unspecified, initial encounter, T80.49XA — Other Rh incompatibility reaction due to transfusion of blood or blood products, initial encounter, T80.910A — Acute hemolytic transfusion reaction, unspecified incompatibility, initial encounter, T80.911A — Delayed hemolytic transfusion reaction, unspecified incompatibility, initial encounter, T80.92XA — Unspecified transfusion reaction, initial encounter, T80.A0XA — Non-ABO incompatibility reaction due to transfusion of blood or blood products, unspecified, initial encounter, T80.A10A — Non-ABO incompatibility with acute hemolytic transfusion reaction, initial encounter, T80.A11A — Non-ABO incompatibility with delayed hemolytic transfusion reaction, initial encounter, T80.A19A — Non-ABO incompatibility with hemolytic transfusion reaction, unspecified, initial encounter, T80.A9XA — Other non-ABO incompatibility reaction due to transfusion of blood or blood products, initial encounter

Same injury, other encounter phase

Same injury, coded at a different phase of treatment via the 7th character.

T80.919D — Hemolytic transfusion reaction, unspecified incompatibility, unspecified as acute or delayed, subsequent encounterCompare T80.919A vs T80.919D →, T80.919S — Hemolytic transfusion reaction, unspecified incompatibility, unspecified as acute or delayed, sequelaCompare T80.919A vs T80.919S →

Same clinical category (CCSR)

AHRQ's Clinical Classifications Software groups these diagnoses under the same clinical category (Complication of other surgical or medical care, injury, initial encounter).

T80.61XA — Other serum reaction due to administration of blood and blood products, initial encounter, T80.62XA — Other serum reaction due to vaccination, initial encounter, T80.69XA — Other serum reaction due to other serum, initial encounter, T80.810A — Extravasation of vesicant antineoplastic chemotherapy, initial encounter, T80.818A — Extravasation of other vesicant agent, initial encounter, T80.82XA — Complication of immune effector cellular therapy, initial encounter, T80.89XA — Other complications following infusion, transfusion and therapeutic injection, initial encounter, T80.90XA — Unspecified complication following infusion and therapeutic injection, initial encounter, T80.910A — Acute hemolytic transfusion reaction, unspecified incompatibility, initial encounter, T80.911A — Delayed hemolytic transfusion reaction, unspecified incompatibility, initial encounter, T80.92XA — Unspecified transfusion reaction, initial encounter, T80.A0XA — Non-ABO incompatibility reaction due to transfusion of blood or blood products, unspecified, initial encounter, T80.A10A — Non-ABO incompatibility with acute hemolytic transfusion reaction, initial encounter, T80.A11A — Non-ABO incompatibility with delayed hemolytic transfusion reaction, initial encounter, T80.A19A — Non-ABO incompatibility with hemolytic transfusion reaction, unspecified, initial encounter, T80.A9XA — Other non-ABO incompatibility reaction due to transfusion of blood or blood products, initial encounter, T81.10XA — Postprocedural shock unspecified, initial encounter, T81.11XA — Postprocedural cardiogenic shock, initial encounter, T81.12XA — Postprocedural septic shock, initial encounter, T81.19XA — Other postprocedural shock, initial encounter, +230 more

Lab tests where this diagnosis supports Medicare coverage (NCD)

Medicare's National Coverage Determination (NCD) program lists this diagnosis as medical justification for these lab tests.

Iron Panel, Prothrombin Time Test and INR (PT/INR)

Contextual Map

Every relationship of T80.919A in one view: hierarchy, official tabular instructions in both directions, clinical classification, risk adjustment, MS-DRG participation, index terms and change history — each edge carrying the CMS source it derives from.

Run T80.919A with these 6 related codes in Claim Check

Hierarchy

• S00-T88 — Chapter 19: Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88) (S00-T88)[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T80-T88 — Complications of surgical and medical care, not elsewhere classified[Hierarchy]— CMS ICD-10-CM tabular structure · icd10cm-fy2026

Referenced by Excludes1 notes

• T88.7 — Unspecified adverse effect of drug or medicament[Excludes1](via T80.-): “specified adverse effects of drugs and medicaments (A00-R94 and T80-T88.6, T88.8)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Referenced by Excludes2 notes

• T45.8 — Poisoning by, adverse effect of and underdosing of other primarily systemic and hematological agents[Excludes2](via T80.-): “transfusion reactions (T80.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T78 — Adverse effects, not elsewhere classified[Excludes2](via T80.-): “complications of surgical and medical care NEC (T80-T88)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T79 — Certain early complications of trauma, not elsewhere classified[Excludes2](via T80.-): “complications occurring during or following medical procedures (T80-T88)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T81 — Complications of procedures, not elsewhere classified[Excludes2](via T80.-): “complications following infusion, transfusion and therapeutic injection (T80.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026
• T88 — Other complications of surgical and medical care, not elsewhere classified[Excludes2](via T80.-): “complication following infusion, transfusion and therapeutic injection (T80.-)”— CMS ICD-10-CM tabular instructional notes · icd10cm-fy2026

Clinical classification (CCSR)

• INJ037 — Complication of other surgical or medical care, injury, initial encounter[CCSR]— AHRQ CCSR for ICD-10-CM Diagnoses (HCUP)

MS-DRG Grouper

• CC — Complication or Comorbidity [MS-DRG severity]: “As a secondary diagnosis this code can raise the stay's MS-DRG severity tier (CC).”— CMS MS-DRG Definitions Manual (Appendix C) · FY2026
• DRG 791 — PREMATURITY WITH MAJOR PROBLEMS[MS-DRG]: “PREMATURITY WITH MAJOR PROBLEMS (MDC 15)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 793 — FULL TERM NEONATE WITH MAJOR PROBLEMS[MS-DRG]: “FULL TERM NEONATE WITH MAJOR PROBLEMS (MDC 15)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 811 — RED BLOOD CELL DISORDERS WITH MCC[MS-DRG]: “RED BLOOD CELL DISORDERS WITH MCC (MDC 16)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026
• DRG 812 — RED BLOOD CELL DISORDERS WITHOUT MCC[MS-DRG]: “RED BLOOD CELL DISORDERS WITHOUT MCC (MDC 16)”— CMS MS-DRG Definitions Manual (Appendix B) · FY2026

MDC crossing

• MDC 15 — Newborns and Other Neonates with Conditions Originating in Perinatal Period[MDC crossing]: “Newborns and Other Neonates with Conditions Originating in Perinatal Period — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs.”— CMS MS-DRG Definitions Manual · FY2026
• MDC 16 — Diseases and Disorders of Blood, Blood Forming Organs and Immunologic Disorders[MDC crossing]: “Diseases and Disorders of Blood, Blood Forming Organs and Immunologic Disorders — the grouper's crossing between diagnoses and procedures: a principal diagnosis sets the MDC, and same-MDC procedures move the stay to its surgical DRGs. 1,614 same-MDC procedures group here; browse them on the MDC page.”— CMS MS-DRG Definitions Manual · FY2026

Index entries

• Complication (s) (from) (of), transfusion (blood) (lymphocytes) (plasma), hemolytic reaction (antigen unspecified)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026
• Complication (s) (from) (of), transfusion (blood) (lymphocytes) (plasma), incompatibility reaction (antigen unspecified)[Index term]— CMS ICD-10-CM Index to Diseases and Injuries · icd10cm-fy2026

Nearest codes (40)

• T80 — Complications following infusion, transfusion and therapeutic injection[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T80.82XS — Complication of immune effector cellular therapy, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T80.89 — Other complications following infusion, transfusion and therapeutic injection[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T80.89XA — Other complications following infusion, transfusion and therapeutic injection, initial encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T80.89XD — Other complications following infusion, transfusion and therapeutic injection, subsequent encounter[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T80.89XS — Other complications following infusion, transfusion and therapeutic injection, sequela[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T80.9 — Unspecified complication following infusion, transfusion and therapeutic injection[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• T80.90 — Unspecified complication following infusion and therapeutic injection[Sibling]— CMS ICD-10-CM tabular structure · icd10cm-fy2026
• and 32 more

Change history

• FY2016 — In the code set at ICD-10-CM adoption [Change history]— CMS release files (code change ledger) · icd10cm-fy2016

Common coding questions

Sources for this page

Codes, titles, notes, index terms and mappings on this page are transcribed from the datasets below. Relationships MedCoder computed and text MedCoder wrote are labelled where they appear.

Code, title, tabular notes and index terms Official source data

CMS/CDC ICD-10-CM FY2026 tabular list, index and tables, effective October 1, 2025 Release, file and checksum · Publisher’s page

Claim edits Official source data

CMS Definitions of Medicare Code Edits — v43.1 (April 2026) Release, file and checksum · Publisher’s page

Inpatient payment groups Official source data

CMS MS-DRG Definitions Manual (incl. Appendix B diagnosis index, Appendix C CC/MCC list, Appendix E procedure index) and IPPS Final Rule tables — v43 Release, file and checksum · Publisher’s page

Change history and date-of-service validity Official source data

CMS ICD-10-CM release addenda, ingested release by release into the change ledger Release, file and checksum · Publisher’s page

Comparisons, relationships and the contextual map MedCoder structured relationship

Computed by MedCoder from the tabular notes and tables above; every derived relationship is marked as derived where it appears

Summary and FAQ answers MedCoder explanation

Written by MedCoder to explain the sources above: drafted with AI assistance, checked by a person against the release files, and labelled as MedCoder text where it appears. Not official text.

Labels on this page: Official source data · MedCoder structured relationship · MedCoder explanation. How to read the labels · All data sources and release dates

Nearest Codes in This Family

Official ICD-10-CM classifications closest to T80.919A in its code family, with their registry titles.

• T80.911 — Delayed hemolytic transfusion reaction, unspecified incompatibility
• T80.911A — Delayed hemolytic transfusion reaction, unspecified incompatibility, initial encounter
• T80.911D — Delayed hemolytic transfusion reaction, unspecified incompatibility, subsequent encounter
• T80.911S — Delayed hemolytic transfusion reaction, unspecified incompatibility, sequela
• T80.919 — Hemolytic transfusion reaction, unspecified incompatibility, unspecified as acute or delayed
• T80.919D — Hemolytic transfusion reaction, unspecified incompatibility, unspecified as acute or delayed, subsequent encounter
• T80.919S — Hemolytic transfusion reaction, unspecified incompatibility, unspecified as acute or delayed, sequela
• T80.92 — Unspecified transfusion reaction
• T80.92XA — Unspecified transfusion reaction, initial encounter
• T80.92XD — Unspecified transfusion reaction, subsequent encounter

View all codes in the T80 family