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T78.3XXS vs T80.6

T78.3XXS (Angioneurotic edema, sequela) compared with T80.6 (Other serum reactions), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.

Can these codes be reported together?

No — do not report together. T78.3XXS carries an Excludes1 note covering T80.6: “serum urticaria (T80.6-)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Yes, when both are documented. T78.3XXS carries an Excludes2 note covering T80.6: “complications of surgical and medical care NEC (T80-T88)”

Excludes2 marks distinct conditions — both may be reported when both are documented.

Side by side

T78.3XXSAngioneurotic edema, sequelaT80.6Other serum reactions
Billing statusBillableNon-billable header
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)
DefinitionAngioneurotic edema, sequela is a billable ICD-10-CM diagnosis code (T78.3S).Other serum reactions is a non-billable ICD-10-CM category code (T80.6).
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 T80
Includes
Allergic angioedema
Giant urticaria
Quincke's edema
complications following perfusion
Intoxication by serum
Protein sickness
Serum rash
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