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  6. 2026 ICD-10-CM Code T78.089S

2026 ICD-10-CM Diagnosis Code T78.089S

Anaphylactic reaction due to eggs, unspecified, sequela

ICD-10-CM Code:
T78.089S
ICD-10 Code for:
Anaphylactic reaction due to eggs, unspecified, sequela
Is Billable?
Yes - Valid for Submission
Code Navigator:

T78.089S is a billable diagnosis code used to specify a medical diagnosis of anaphylactic reaction due to eggs, unspecified, sequela. The code is valid during the current fiscal year for the submission of HIPAA-covered transactions from October 01, 2025 through September 30, 2026. The code is exempt from present on admission (POA) reporting for inpatient admissions to general acute care hospitals.

T78.089S is a sequela code, includes a 7th character and should be used for complications that arise as a direct result of a condition like anaphylactic reaction due to eggs unspecified. According to ICD-10-CM Guidelines a "sequela" code should be used for chronic or residual conditions that are complications of an initial acute disease, illness or injury. The most common sequela is pain. Usually, two diagnosis codes are needed when reporting sequela. The first code describes the nature of the sequela while the second code describes the sequela or late effect.

Unspecified diagnosis codes like T78.089S are acceptable when clinical information is unknown or not available about a particular condition. Although a more specific code is preferable, unspecified codes should be used when such codes most accurately reflect what is known about a patient's condition. Specific diagnosis codes should not be used if not supported by the patient's medical record.

Code Classification

  • Injury, poisoning and certain other consequences of external causes
    S00–T88
    • Other and unspecified effects of external causes
      T66-T78
      • Adverse effects, not elsewhere classified
        T78

Approximate Synonyms

The following list of clinical terms are approximate synonyms, alternative descriptions, or common phrases that might be used by patients, healthcare providers, or medical coders to describe the same condition. These synonyms and related diagnosis terms are often used when searching for an ICD-10 code, especially when the exact medical terminology is unclear. Whether you're looking for lay terms, similar diagnosis names, or common language alternatives, this list can help guide you to the correct ICD-10 classification.

  • Anaphylaxis caused by egg
  • Egg white-induced anaphylaxis

Coding Guidelines

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 aplicable episode of care:

  • A - initial encounter
  • D - subsequent encounter
  • S - sequela

New 2026 ICD-10-CM Code

T78.089S is new to ICD-10-CM code set for the FY 2026, effective October 1, 2025. The National Center for Health Statistics (NCHS) has published an update to the ICD-10-CM diagnosis codes which became effective October 1, 2025. This is a new and revised code for the FY 2026 (October 1, 2025 - September 30, 2026).

Present on Admission (POA)

T78.089S is exempt from POA reporting - The Present on Admission (POA) indicator is used for diagnosis codes included in claims involving inpatient admissions to general acute care hospitals. POA indicators must be reported to CMS on each claim to facilitate the grouping of diagnoses codes into the proper Diagnostic Related Groups (DRG). CMS publishes a listing of specific diagnosis codes that are exempt from the POA reporting requirement. Review other POA exempt codes here.

CMS POA Indicator Options and Definitions

POA Indicator: Y

Reason: Diagnosis was present at time of inpatient admission.

CMS Pays CC/MCC DRG? YES

POA Indicator: N

Reason: Diagnosis was not present at time of inpatient admission.

CMS Pays CC/MCC DRG? NO

POA Indicator: U

Reason: Documentation insufficient to determine if the condition was present at the time of inpatient admission.

CMS Pays CC/MCC DRG? NO

POA Indicator: W

Reason: Clinically undetermined - unable to clinically determine whether the condition was present at the time of inpatient admission.

CMS Pays CC/MCC DRG? YES

POA Indicator: 1

Reason: Unreported/Not used - Exempt from POA reporting.

CMS Pays CC/MCC DRG? NO

Replacement Code

T78089S replaces the following previously assigned ICD-10-CM code(s):

  • T78.08XS - Anaphylactic reaction due to eggs, sequela

Code History

  • FY 2026 - Code Added, effective from 10/1/2025 through 9/30/2026