T78.3XXA — Angioneurotic edema, initial encounter
T78.3XXA

What this code means
Angioneurotic oedema (angioedema) is rapid swelling of the deeper skin and mucous membranes, often of lips, tongue or airway; first encounter.
Also called: angioedema, angioneurotic edema.
When this code is used
Used for angioneurotic oedema, initial encounter.
Where it sits in ICD-10-CM
Code T78.3XXA belongs to Chapter 19: Injury, poisoning and certain other consequences of external causes, which covers codes S00–T88 in the FY2027 ICD-10-CM tabular list. The official description above is copied verbatim from the CDC/NCHS FY2027 code file.
Related symptoms
Frequently asked questions
What is ICD-10-CM code T78.3XXA?
T78.3XXA is the ICD-10-CM diagnosis code for “Angioneurotic edema, initial encounter”. Angioneurotic oedema (angioedema) is rapid swelling of the deeper skin and mucous membranes, often of lips, tongue or airway; first encounter.
When is code T78.3XXA used?
Used for angioneurotic oedema, initial encounter. It belongs to Chapter 19 of ICD-10-CM (Injury, poisoning and certain other consequences of external causes).
This guide explains ICD-10-CM codes in plain language for patients, students and other readers. It is educational information only — not coding, billing or medical advice. The code recorded for any real encounter is assigned from the full clinical documentation by the treating team and qualified coders, and only they can decide which code fits a specific case.
More codes in Chapter 19
S00.93XA — Contusion of unspecified part of head, initial encounter
S01.01XA — Laceration without foreign body of scalp, initial encounter
S02.2XXA — Fracture of nasal bones, initial encounter for closed fracture
S05.01XA — Injury of conjunctiva and corneal abrasion without foreign body, right eye, initial encounter
S06.0X0A — Concussion without loss of consciousness, initial encounter
S09.90XA — Unspecified injury of head, initial encounter