T78.089S — Anaphylactic reaction due to eggs, unspecified, sequela
T78.089S is a billable, specific ICD-10-CM code for anaphylactic reaction due to eggs, unspecified, 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
Risk adjustment
T78.089S 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
T78.089S is named in 21 Medicare coverage policies — 21 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A56559Billing and Coding: Allergy Skin Testing
- A56559Billing and Coding: Allergy Skin Testing
- A56612Billing and Coding: CT of the Head
- A56844Billing and Coding: RAST Type Tests
Code history
What changed, and when. Derived by diffing consecutive CMS release files — which matters when you are defending a code assigned under an earlier edition.
- addedFY2024-FY2026
Anaphylactic reaction due to eggs, unspecified, sequela
Related codes at this level
Codes that share T78.089. If T78.089S is not quite right, the correct code is usually one of these.
Questions about T78.089S
- Is T78.089S a billable ICD-10-CM code?
- Yes. T78.089S is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does T78.089S 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).