2027 ICD-10-CM Diagnosis Code Z91.0111Allergy to milk products with tolerance to baked milk

ICD-10-CM Codes›Z00–Z99›Z77-Z99›Z91

ICD-10-CM Z91.0111
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

Z91.0111 is a billable ICD-10-CM diagnosis code for allergy to milk products with tolerance to baked milk. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 951. The code is not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified status.

Code Identity

ICD-10-CM Code
Z91.0111
Billable Status
Yes — Valid for Submission
Code Describes
Allergy to milk products with tolerance to baked milk
Short Description
Allergy to milk products with tolerance to baked milk
Same as the full description in the CMS dataset.
Parent Code
Z91.011
Allergy to milk products

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ77-Z99Persons with potential health hazards related to family and personal history and certain conditions influencing health status
CategoryZ91Personal risk factors, not elsewhere classified
This CodeZ91.0111Allergy to milk products with tolerance to baked milk

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z91.0111.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Present on Admission (POA)Billing

Z91.0111 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review the other POA exempt codes in Persons with potential health hazards related to family and personal history and certain conditions influencing health status (Z77-Z99).

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Z91.0111: its own notes plus those printed at Z91.011, Z91.01, Z91.0, Z91, block Z77-Z99, and Chapter 21. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

On Z91.0111 itself
  • Allergy to milk products with reactivity to baked milk (Z91.0112)
From Z91.011 Allergy to milk products applies to 3 codes
  • lactose intolerance (E73.-)

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Z91.01 Food allergy status applies to 10 codes
  • food additives allergy status (Z91.02)
From Z91.0 Allergy status, other than to drugs and biological substances applies to 17 codes
  • Allergy status to drugs, medicaments, and biological substances (Z88.-)
From Z91 Personal risk factors, not elsewhere classified applies to 62 codes
  • 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-)

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

From Block Z77-Z99 Persons with potential health hazards related to family and personal history and certain conditions influencing health status applies to 567 codes
  • any follow-up examination (Z08-Z09)

Notes

General instructions on how these codes are used.

From Chapter 21 (Z00-Z99) Factors influencing health status and contact with health services applies to 1,425 codes
  • Z codes represent reasons for encounters. A corresponding procedure code must accompany a Z code if a procedure is performed. Categories Z00-Z99 are provided for occasions when circumstances other than a disease, injury or external cause classifiable to categories A00-Y89 are recorded as 'diagnoses' or 'problems'. This can arise in two main ways:
  • (a) When a person who may or may not be sick encounters the health services for some specific purpose, such as to receive limited care or service for a current condition, to donate an organ or tissue, to receive prophylactic vaccination (immunization), or to discuss a problem which is in itself not a disease or injury.
  • (b) When some circumstance or problem is present which influences the person's health status but is not in itself a current illness or injury.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name Z91.0111, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming Z91.0111: they are not reported together with it, unless the two conditions are unrelated.

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

Excludes2 1

These codes carry an Excludes2 note naming Z91.0111: its condition is not part of those codes, and both may be reported when the patient has both.

  • Z88 Allergy status to drugs, medicaments and biological substances
    Allergy status, other than to drugs and biological substances (Z91.0-) names Z91.0-, which includes this code

Use Additional Code 2

These codes say to use an additional code from the note, and Z91.0111 is one of the codes named.

  • D89.44 Hereditary alpha tryptasemia
    allergy status, other than to drugs and biological substances (Z91.0-) names Z91.0-, which includes this code
  • K52.2 Allergic and dietetic gastroenteritis and colitis
    code to identify type of food allergy (Z91.01-, Z91.02-) names Z91.01-, which includes this code

Code Also 1

These codes say Z91.0111 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • Z87.892 Personal history of anaphylaxis
    allergy status, other than to drugs and biological substances (Z91.0-) names Z91.0-, which includes this code

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR FAC025
Other specified status
Default principal diagnosis: inpatient No · outpatient Yes

Patient EducationClinical

Food Allergy

A food allergy is an abnormal immune system reaction to certain foods. Your immune system normally protects you from germs. But if you have a food allergy, your immune system mistakenly reacts to certain foods as if they were harmful. This reaction is usually mild. But in some cases, it can be serious or even life-threatening.

The full article covers:

  • What is a food allergy?
  • Who is more likely to develop a food allergy?
  • What are the symptoms of food allergies?
  • How are food allergies diagnosed?
  • What are the treatments for food allergies?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code History & ChangesHistory

Replacement Z91.0111 replaces the following previously assigned code(s):

  • Z91.011 - Allergy to milk products
FY 2026AddedAdded to the ICD-10-CM code setEffective October 1, 2025.
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About Z91.0111Overview

What is the ICD-10 code for allergy to milk products with tolerance to baked milk?

The ICD-10-CM code for allergy to milk products with tolerance to baked milk is Z91.0111 (sometimes written as Z910111). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is Z91.0111 (Allergy to milk products) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report allergy to milk products with tolerance to baked milk on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does Z91.0111 group to?

On inpatient claims, allergy to milk products with tolerance to baked milk maps to MS-DRG 951 (other Factors Influencing Health Status), which carries a relative weight of 0.5574. Higher weights mean higher Medicare reimbursement.

Can Z91.0111 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because allergy to milk products with tolerance to baked milk describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z91.0111 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for allergy to milk products with tolerance to baked milk on inpatient claims. The code appears in the Persons with potential health hazards related to family and personal history and certain conditions influencing health status (Z77-Z99) range of the CMS exempt list.