MCMCB Pro
Z91.011

Z91.011Allergy to milk products

Non-billable headerICD-10-CM

Z91.011 is a non-billable header ICD-10-CM code for allergy to milk products. It cannot be billed on its own: choose one of the more specific child codes below.

Excludes1 — never code together

These conditions cannot occur together. Billing both on the same encounter is a denial.

  • lactose intolerance (E73.-)

Other codes that can never be billed with Z91.011

These codes carry an Excludes1 note pointing at Z91.011. The conflict binds both ways, but ICD-10-CM only writes it down on one side — so you would not find this by reading Z91.011 alone.

  • Z91.0111Allergy to milk products with tolerance to baked milk
  • Z91.0112Allergy to milk products with reactivity to baked milk

Risk adjustment

Z91.011 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 Z91.011

3 child codes. Green means billable.

Related codes at this level

Codes that share Z91.01. If Z91.011 is not quite right, the correct code is usually one of these.

Questions about Z91.011

Is Z91.011 a billable ICD-10-CM code?
No. Z91.011 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does Z91.011 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 Z91.011?
Z91.011 carries an Excludes1 note, which means the conditions it lists can never be coded together with it on the same encounter.
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.