T80.311A vs T80.311D

T80.311A (ABO incompatibility with delayed hemolytic transfusion reaction, initial encounter) compared with T80.311D (ABO incompatibility with delayed hemolytic transfusion reaction, subsequent encounter), from the official CMS tabular data. T80.311A and T80.311D code the same injury at a different phase of treatment.

Relationship

Review

Encounter relationship

T80.311A

Initial encounter

ABO incompatibility with delayed hemolytic transfusion reaction, initial encounter

↔

T80.311D

Subsequent encounter

ABO incompatibility with delayed hemolytic transfusion reaction, subsequent encounter

Same underlying diagnosis, different encounter phase.

The 7th character records the phase of care for the encounter being coded, so a single encounter takes one of these characters, not several. Review whether both phases belong on the same episode of care.

Source: ICD-10-CM Official Guidelines, Section I.C.19.a

Can these codes be reported together?

Same injury, other encounter phase. T80.311A and T80.311D code the same injury at a different phase of treatment, set by the 7th character.

The 7th character records the type of care given at the encounter being coded (ICD-10-CM Official Guidelines, Section I.C.19.a), so one encounter takes one of these, not both.

Side by side

	T80.311AABO incompatibility with delayed hemolytic transfusion reaction, initial encounter	T80.311DABO incompatibility with delayed hemolytic transfusion reaction, subsequent encounter
Billing status	Billable	Billable
Classification	S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)	S00-T88 — Injury, Poisoning and Certain Other Consequences of External Causes (S00-T88)
Definition	ABO incompatibility with delayed hemolytic transfusion reaction, initial encounter is a billable ICD-10-CM diagnosis code (T80.311A).	ABO incompatibility with delayed hemolytic transfusion reaction, subsequent encounter is a billable ICD-10-CM diagnosis code (T80.311D).
7th character	The appropriate 7th character is to be added to each code from category T80	The appropriate 7th character is to be added to each code from category T80
Includes	complications following perfusion ABO incompatibility with hemolytic transfusion reaction 24 hours or more after transfusion Delayed hemolytic transfusion reaction (DHTR) due to ABO incompatibility	complications following perfusion ABO incompatibility with hemolytic transfusion reaction 24 hours or more after transfusion Delayed hemolytic transfusion reaction (DHTR) due to ABO incompatibility
Use additional code	code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5) code(s) to identify the specified condition resulting from the complication code to identify devices involved and details of circumstances (Y62-Y82)	code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5) code(s) to identify the specified condition resulting from the complication code to identify devices involved and details of circumstances (Y62-Y82)

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Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources