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  6. 2026 ICD-10-CM Code Z91.0122

2026 ICD-10-CM Diagnosis Code Z91.0122

Allergy to eggs with reactivity to baked egg

ICD-10-CM Code:
Z91.0122
ICD-10 Code for:
Allergy to eggs with reactivity to baked egg
Is Billable?
Yes - Valid for Submission
Code Navigator:

Z91.0122 is a billable diagnosis code used to specify a medical diagnosis of allergy to eggs with reactivity to baked egg. 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.

This code describes a circumstance which influences the patient's health status but not a current illness or injury. The code is unacceptable as a principal diagnosis.

Code Classification

  • Factors influencing health status and contact with health services
    Z00–Z99
    • Persons with potential health hazards related to family and personal history and certain conditions influencing health status
      Z77-Z99
      • Personal risk factors, not elsewhere classified
        Z91

New 2026 ICD-10-CM Code

Z91.0122 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).

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Type 1 Excludes

Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
  • Allergy to egg with tolerance to baked egg Z91.0121

Index to Diseases and Injuries References

The following annotation back-references for this diagnosis code are found in the injuries and diseases index. The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10-CM code(s).

Index of External Cause of Injuries

References found for this diagnosis code in the External Cause of Injuries Index:

    • Allergy, allergic(reaction) (to)
      • food (any) (ingested) NEC
        • status (without reaction)
          • eggs
            • with
              • reactivity to baked egg
    • History
      • personal (of)
        • allergy (to)
          • food
            • eggs
              • with
                • reactivity to baked egg

Code Edits

The Medicare Code Editor (MCE) detects errors and inconsistencies in ICD-10-CM diagnosis coding that can affect Medicare claim validity. These Medicare code edits help medical coders and billing professionals determine when a diagnosis code is not appropriate as a principal diagnosis, does not meet coverage criteria. Use this list to verify whether a code is valid for Medicare billing and to avoid claim rejections or denials due to diagnosis coding issues.

Unacceptable principal diagnosis

There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

View Edit

Present on Admission (POA)

Z91.0122 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

Z910122 replaces the following previously assigned ICD-10-CM code(s):

  • Z91.012 - Allergy to eggs

Code History

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