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Z91.0

Z91.0Allergy status, other than to drugs and biological substances

Non-billable headerICD-10-CM

Z91.0 is a non-billable header ICD-10-CM code for allergy status, other than to drugs and biological substances. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes2 — not included here, but may coexist

The excluded condition is not part of this code, but a patient can have both. You may code both.

  • Allergy status to drugs, medicaments, and biological substances (Z88.-)

Other codes that can never be billed with Z91.0

These codes carry an Excludes1 note pointing at Z91.0. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading Z91.0 alone.

  • Z91.0111Allergy to milk products with tolerance to baked milk
  • Z91.0112Allergy to milk products with reactivity to baked milk
  • Z91.0121Allergy to eggs with tolerance to baked egg
  • Z91.0122Allergy to eggs with reactivity to baked egg

Risk adjustment

Z91.0 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.

Code to one of these instead Z91.0

5 child codes. Green means billable.

Related codes at this level

Codes that share Z91. If Z91.0 is not quite right, the correct code is usually one of these.

Questions about Z91.0

Is Z91.0 a billable ICD-10-CM code?
No. Z91.0 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does Z91.0 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).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.