T78.2 vs T80
T78.2 and T80 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on T78.2
anaphylactic reaction or shock due to serum (T80.5-)
T78.2
Anaphylactic shock, unspecified
Not billable
- Chapter 19
- Injury, poisoning and certain other consequences of external causes
- Section
- T66-T78
Use when the record says
- Allergic shock
- Anaphylactic reaction
- Anaphylaxis
Indexed under
- Allergy, allergic › anaphylactic reaction or shock (reaction) (to)
- Allergy, allergic › shock (reaction) (to)
- Shock › anaphylactic
T80
Complications following infusion, transfusion and therapeutic injection
Not billable
- Chapter 19
- Injury, poisoning and certain other consequences of external causes
- Section
- T80-T88
Use when the record says
- complications following perfusion
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027