T78.41XA vs T78.41XS
T78.41XA (Arthus phenomenon, initial encounter) compared with T78.41XS (Arthus phenomenon, sequela), from the official CMS tabular data. T78.41XA and T78.41XS code the same injury at a different phase of treatment.
Can these codes be reported together?
Same injury, other encounter phase. T78.41XA and T78.41XS 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
| T78.41XAArthus phenomenon, initial encounter | T78.41XSArthus phenomenon, sequela | |
|---|---|---|
| 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 | Arthus phenomenon, initial encounter is a billable ICD-10-CM diagnosis code (T78.41A). | Arthus phenomenon, sequela is a billable ICD-10-CM diagnosis code (T78.41S). |
| 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 T78 |
| Includes | Arthus reaction | Arthus reaction |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources