Z91.0121 — Allergy to eggs with tolerance to baked egg
Z91.0121 is a billable, specific ICD-10-CM code for allergy to eggs with tolerance to baked egg. It is valid for submission on a claim.
Excludes1 — never code together
These conditions cannot occur together. Billing both on the same encounter is a denial.
- Allergy to eggs with reactivity to baked egg (Z91.0122)
Other codes that can never be billed with Z91.0121
These codes carry an Excludes1 note pointing at Z91.0121. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading Z91.0121 alone.
- Z91.0122Allergy to eggs with reactivity to baked egg
Risk adjustment
Z91.0121 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.
Medicare coverage
Z91.0121 is named in 19 Medicare coverage policies — 19 listing it as supporting medical necessity. Which of them applies to you depends on your Medicare contractor, and coverage genuinely differs by state.
- A56558Billing and Coding: Allergy Testing
- A56558Billing and Coding: Allergy Testing
- A56558Billing and Coding: Allergy Testing
- A56559Billing and Coding: Allergy Skin Testing
How Z91.0121 is indexed
Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to Z91.0121.
- Allergy, allergic›food NEC›status›eggs›with›tolerance to baked egg
- History›personal›allergy›food›eggs›with›tolerance to baked egg
Related codes at this level
Codes that share Z91.012. If Z91.0121 is not quite right, the correct code is usually one of these.
Questions about Z91.0121
- Is Z91.0121 a billable ICD-10-CM code?
- Yes. Z91.0121 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
- Where does Z91.0121 sit in the tabular list?
- Factors influencing health status and contact with health services (Z00-Z99), in the block Persons with potential health hazards related to family and personal history and certain conditions influencing health status (Z77-Z99).
- What cannot be coded together with Z91.0121?
- Z91.0121 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.