2026 ICD-10-CM Diagnosis Code T78.080SAnaphylactic reaction due to egg with tolerance to baked egg, sequela

ICD-10-CM Codes›S00–T88›T66-T78›T78

ICD-10-CM T78.080S
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T78.080S is a billable ICD-10-CM diagnosis code for anaphylactic reaction due to egg with tolerance to baked egg, 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.

Code Identity

ICD-10-CM Code
T78.080S
Billable Status
Yes — Valid for Submission
Code Describes
Anaphylactic reaction due to egg with tolerance to baked egg, sequela
Short Description
Anaphyl react due to egg with tolerance to baked egg, sqla
Parent Code
T78.080
Anaphylactic reaction due to egg with tolerance to baked egg

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT66-T78Other and unspecified effects of external causes
CategoryT78Adverse effects, not elsewhere classified
This CodeT78.080SAnaphylactic reaction due to egg with tolerance to baked egg, sequela

Present on Admission (POA)Billing

T78.080S is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

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 T78.080S was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.

Replacement T78.080S replaces the following previously assigned code(s):

  • T78.08XS - Anaphylactic reaction due to eggs, sequela
FY 2026AddedAdded to the ICD-10-CM code setEffective October 1, 2025.
FY 2026CurrentRevised in the current code setEffective October 1, 2025 through September 30, 2026.

Questions About T78.080SOverview

Is T78.080S (Anaphylactic reaction due to egg with tolerance to baked egg) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report anaphylactic reaction due to egg with tolerance to baked egg, sequela on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character S in T78.080S mean?

The final character S makes this a sequela code: it reports a lingering problem that remains after the anaphylactic reaction due to egg with tolerance to baked egg itself has resolved, not the original event.

What MS-DRG does T78.080S group to?

When anaphylactic reaction due to egg with tolerance to baked egg, 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 T78.080S 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 egg with tolerance to baked egg, sequela on inpatient claims.