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ICD-10-CM 2027 diagnosis code

Z91.0122Allergy to eggs with reactivity to baked egg

✓ Billable / specificPOA exemptNot a principal dx

Z91.0122 is a valid, billable ICD-10-CM code for allergy to eggs with reactivity to baked egg. It can be reported on claims for dates of service from October 1, 2026 – September 30, 2027.

Code last changed in FY2026 (effective October 1, 2025). Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About Z91.0122

Z91.0122 is the ICD-10-CM diagnosis code for allergy to eggs with reactivity to baked egg. It belongs to category Z91 (personal risk factors, not elsewhere classified), block Z77-Z99 (persons with potential health hazards related to family and personal history and certain conditions influencing health status) and chapter 21 (factors influencing health status and contact with health services). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within Z91.012 (allergy to eggs), Z91.0122 is specifically for allergy to eggs with reactivity to baked egg. Related codes cover unspecified (Z91.0120) and with tolerance to baked egg (Z91.0121).

Don't report Z91.0122 together with the conditions in its Excludes1 note: Allergy to egg with tolerance to baked egg (Z91.0121).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 951 (Other Factors Influencing Health Status, relative weight 0.5577), in MDC 23 (Factors Influencing Health Status and Other Contacts with Health Services), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.

It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.

It was added in FY2026, effective October 1, 2025.

Coding notes

Excludes1Not coded here — never report together with this code
  • Allergy to egg with tolerance to baked egg (Z91.0121)

Notes that apply from higher levels

Instructions written at a parent level also apply to Z91.0122.

› From Z91.01 Food allergy status
Excludes2
  • food additives allergy status (Z91.02)
› From Z91.0 Allergy status, other than to drugs and biological substances
Excludes2
  • Allergy status to drugs, medicaments, and biological substances (Z88.-)
› From Z91 Personal risk factors, not elsewhere classified
Excludes2
  • contact with and (suspected) exposures hazardous to health (Z77.-)
  • exposure to pollution and other problems related to physical environment (Z77.1-)
  • female genital mutilation status (N90.81-)
  • occupational exposure to risk factors (Z57.-)
  • personal history of physical injury and trauma (Z87.81, Z87.82-)

Broader instructions also apply from Z77-Z99 Persons with potential health hazards related to family and personal history and certain conditions influencing health status and Chapter 21: Factors influencing health status and contact with health services.

Alphabetic index entries

2 entries

Terms in the official ICD-10-CM index that lead to Z91.0122.

Codes whose notes reference Z91.0122

MS-DRG v44.0 grouping

All DRGs →

Inpatient MS-DRGs this diagnosis can group to, as the principal or a secondary diagnosis, depending on the rest of the claim.

MDC 23 · Factors Influencing Health Status and Other Contacts with Health Services

Code history

  1. 2016
  2. 2017
  3. 2018
  4. 2019
  5. 2020
  6. 2021
  7. 2022
  8. 2023
  9. 2024
  10. 2025
  11. 2026
  12. 2027
  • FY2026 (effective 10/1/2025): Added
  • No changes since FY2026.

Common questions about Z91.0122

Is Z91.0122 billable?

Yes. Z91.0122 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).

Can Z91.0122 be used as a principal diagnosis?

No. It is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.

Is Z91.0122 a CC or MCC?

No. Z91.0122 is neither a CC nor an MCC under MS-DRG v44.0.

What DRG does Z91.0122 group to?

Z91.0122 is used in the MS-DRG v44.0 logic for MS-DRG 951 (Other Factors Influencing Health Status). Which one applies depends on whether it is the principal diagnosis and on the rest of the claim.