T78.40XA vs T80
T78.40XA (Allergy, unspecified, initial encounter) compared with T80 (Complications following infusion, transfusion and therapeutic injection), from the official CMS tabular data. Both may be reported when both conditions are documented (Excludes2).
Can these codes be reported together?
Yes, when both are documented. T78.40XA carries an Excludes2 note covering T80: “complications of surgical and medical care NEC (T80-T88)”
Excludes2 marks distinct conditions — both may be reported when both are documented.
Side by side
| T78.40XAAllergy, unspecified, initial encounter | T80Complications following infusion, transfusion and therapeutic injection | |
|---|---|---|
| Billing status | Billable | Non-billable header Report instead: T80.0XXA, T80.0XXD, T80.0XXS, T80.1XXA, T80.1XXD |
| 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 | Allergy, unspecified, initial encounter is a billable ICD-10-CM diagnosis code (T78.40A). | Complications following infusion, transfusion and therapeutic injection is a non-billable ICD-10-CM category code (T80). |
| 7th character | The appropriate 7th character is to be added to each code from category T78 | The appropriate 7th character is to be added to each code from category T80 |
| Includes | Allergic reaction NOS Hypersensitivity NOS | complications following perfusion |
| 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) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources