Skip to main content

T78.01XA vs T78.01XS

T78.01XA (Anaphylactic reaction due to peanuts, initial encounter) compared with T78.01XS (Anaphylactic reaction due to peanuts, sequela), from the official CMS tabular data. T78.01XA and T78.01XS code the same injury at a different phase of treatment.

Can these codes be reported together?

Same injury, other encounter phase. T78.01XA and T78.01XS 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

T78.01XAAnaphylactic reaction due to peanuts, initial encounterT78.01XSAnaphylactic reaction due to peanuts, sequela
Billing statusBillableBillable
ClassificationS00-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)
DefinitionAnaphylactic reaction due to peanuts, initial encounter is a billable ICD-10-CM diagnosis code (T78.01A).Anaphylactic reaction due to peanuts, sequela is a billable ICD-10-CM diagnosis code (T78.01S).
7th characterThe appropriate 7th character is to be added to each code from category T78The appropriate 7th character is to be added to each code from category T78

Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources