Skip to main content

T78.02XA vs T78.02XS

T78.02XA (Anaphylactic reaction due to shellfish (crustaceans), initial encounter) compared with T78.02XS (Anaphylactic reaction due to shellfish (crustaceans), sequela), from the official CMS tabular data. T78.02XA and T78.02XS code the same injury at a different phase of treatment.

Can these codes be reported together?

Same injury, other encounter phase. T78.02XA and T78.02XS 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

T78.02XAAnaphylactic reaction due to shellfish (crustaceans), initial encounterT78.02XSAnaphylactic reaction due to shellfish (crustaceans), 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 shellfish (crustaceans), initial encounter is a billable ICD-10-CM diagnosis code (T78.02A).Anaphylactic reaction due to shellfish (crustaceans), sequela is a billable ICD-10-CM diagnosis code (T78.02S).
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