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

Yes. T78.3XXS is a billable, specific ICD-10-CM code and is valid for submission on a claim.

Where does T78.3XXS 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 T78.3XXS?

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

T78.3XXS

T78.3XXS — Angioneurotic edema, sequela

Billable / specific codeICD-10-CMPOA exempt

T78.3XXS is a billable, specific ICD-10-CM code for angioneurotic edema, sequela. It is valid for submission on a claim.

7th character "S" — sequela

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

Risk adjustment

T78.3XXS 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.

Medicare coverage

T78.3XXS is named in 23 Medicare coverage policies — 23 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.

A56558Billing and Coding: Allergy Testing
A56559Billing and Coding: Allergy Skin Testing
A56559Billing and Coding: Allergy Skin Testing
A56559Billing and Coding: Allergy Skin Testing

Related codes at this level

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

Questions about T78.3XXS

Is T78.3XXS a billable ICD-10-CM code?: Yes. T78.3XXS is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does T78.3XXS 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 T78.3XXS?: T78.3XXS carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.