Excludes1 pair
T78.2- vs T80-
T78.2 and T80 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
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
- Allergy, allergic › shock (anaphylactic)
- 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