Is T78.3 a billable ICD-10-CM code?

No. T78.3 is a non-billable header code. Code to a higher level of specificity using one of its child codes.

Where does T78.3 sit in the tabular list?

Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Other and unspecified effects of external causes (T66-T78).

What cannot be coded together with T78.3?

T78.3 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.

T78.3

T78.3 — Angioneurotic edema

Non-billable headerICD-10-CM

T78.3 is a non-billable header ICD-10-CM code for angioneurotic edema. It cannot be billed on its own: choose one of the more specific child codes below. This code also requires a 7th character before it is complete.

This code requires a 7th character

The appropriate 7th character is to be added to each code from category T78

A: initial encounter
D: subsequent encounter
S: sequela

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

serum urticaria (T80.6-)
urticaria (L50.-)

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

Allergic angioedema
Giant urticaria
Quincke's edema

Other codes that can never be billed with T78.3

These codes carry an Excludes1 note pointing at T78.3. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading T78.3 alone.

L50Urticaria
R60Edema, not elsewhere classified

Risk adjustment

T78.3 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

How T78.3 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to T78.3.

Angioedema(allergic) (any site) (with urticaria)
Angioneurotic edema(allergic) (any site) (with urticaria)
Bannister's disease
Quincke's disease or edema
Allergy, allergic›angioneurotic edema
Disease, diseased›Bannister's
Edema, edematous›allergic
Edema, edematous›angioneurotic(allergic) (any site) (with urticaria)
Edema, edematous›circumscribed, acute
Edema, edematous›essential, acute
Edema, edematous›periodic
Edema, edematous›Quincke's

Code to one of these instead T78.3

3 child codes. Green means billable.

Related codes at this level

Codes that share T78. If T78.3 is not quite right, the correct code is usually one of these.

Questions about T78.3

Is T78.3 a billable ICD-10-CM code?: No. T78.3 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does T78.3 sit in the tabular list?: Injury, poisoning and certain other consequences of external causes (S00-T88), in the block Other and unspecified effects of external causes (T66-T78).
What cannot be coded together with T78.3?: T78.3 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.