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 Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter.

Z91.011

Z91.011 — Allergy 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.-)

Excludes2 inherited from the categories above Z91.011

Also inherited, and the opposite of Excludes1: these conditions are not part of Z91.011, but a patient can have both, so you may code both.

Written on Z91.01 — Food allergy status

food additives allergy status (Z91.02)

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

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

Written on Z91 — Personal risk factors, not elsewhere classified

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-)

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 history

What changed, and when. Derived by diffing consecutive CMS release files — which matters when you are defending a code assigned under an earlier edition.

deletedFY2024-FY2026
Allergy to milk products

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 Excludes1 notes, which means the conditions they list can never be coded together with it on the same encounter.