Excludes1 pair
T78.2- vs T79.4-
T78.2 and T79.4 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 T79.4
anaphylactic shock NOS (T78.2)
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
T79.4
Traumatic shock
Not billable
- Chapter 19
- Injury, poisoning and certain other consequences of external causes
- Section
- T79
Use when the record says
- Shock (immediate) (delayed) following injury
Indexed under
- Feeble rapid pulse due to shock following injury
- Decrease › respiration, due to shock following injury
- Hypovolemia › traumatic (shock)
- Pulse › feeble, rapid due to shock following injury
- Rapid › feeble pulse, due to shock, following injury
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