2026 ICD-10-CM Diagnosis Code T78.089SAnaphylactic reaction due to eggs, unspecified, sequela
T78.089S is a billable ICD-10-CM diagnosis code for anaphylactic reaction due to eggs, unspecified, sequela. The 7th character S marks it as a sequela code, which reports a problem that remains after the original condition has resolved. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 922 through 923. The code is exempt from POA reporting. Coders also document this condition as anaphylaxis caused by egg.
Code Identity
Code Classification
Present on Admission (POA)Billing
T78.089S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Anaphylaxis caused by egg
- Egg white-induced anaphylaxis
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Adverse effects, not elsewhere classified (T78). Use the following options for the applicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.
Code History & ChangesHistory
New Code T78.089S was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.
Replacement T78.089S replaces the following previously assigned code(s):
- T78.08XS - Anaphylactic reaction due to eggs, sequela
Questions About T78.089SOverview
Is T78.089S (Anaphylactic reaction due to eggs, unspecified) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report anaphylactic reaction due to eggs, unspecified, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character S in T78.089S mean?
The final character S makes this a sequela code: it reports a lingering problem that remains after the anaphylactic reaction due to eggs, unspecified itself has resolved, not the original event.
What MS-DRG does T78.089S group to?
When anaphylactic reaction due to eggs, unspecified, sequela is the principal diagnosis on an inpatient stay, it groups to MS-DRG 922, 923, with relative weights from 1.0177 to 1.7494 depending on complications. Higher weights mean higher Medicare reimbursement.
Is T78.089S exempt from POA reporting?
Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for anaphylactic reaction due to eggs, unspecified, sequela on inpatient claims.
