2026 ICD-10-CM Diagnosis Code Z91.09Other allergy status, other than to drugs and biological substances

ICD-10-CM Codes›Z00–Z99›Z77-Z99›Z91

ICD-10-CM Z91.09
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z91.09 is a billable ICD-10-CM diagnosis code for other allergy status, other than to drugs and biological substances. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). 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
Z91.09
Billable Status
Yes — Valid for Submission
Code Describes
Other allergy status, other than to drugs and biological substances
Short Description
Oth allergy status, oth than to drugs and biolg substances
Parent Code
Z91.0
Allergy status, other than to drugs and biological substances

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 CodeZ91.09Other allergy status, other than to drugs and biological substances

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z91.09.

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

Z91.09 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Allergy to aluminum
  • Allergy to animal protein
  • Allergy to bird protein
  • Allergy to cattle protein
  • Allergy to citric acid
  • Allergy to Dermatophagoides farinae protein
  • Allergy to Dermatophagoides pteronyssinus protein
  • Allergy to dimethicone
  • Allergy to domestic cat protein
  • Allergy to domestic dog protein
  • Allergy to domestic Guinea pig protein
  • Allergy to dust
  • Allergy to dust mite protein
  • Allergy to fungus
  • Allergy to horse protein
  • Allergy to metal and/or metal compound
  • Allergy to mineral oil
  • Allergy to mugwort pollen
  • Allergy to paraffin
  • Allergy to plant fiber
  • Allergy to pollen
  • Allergy to pyrethroid
  • Allergy to rubber
  • Allergy to rust protein
  • Allergy to silicone
  • Allergy to terpene
  • Allergy to tree resin
  • Allergy to tropomyosin
  • Allergy to wall pellitory pollen
  • Allergy to weed pollen
  • Allergy to white paraffin
  • Allergy to wild rabbit protein
  • Allergy to wood dust
  • Allergy to wool
  • Allergy to wool alcohol
  • Allergy to yellow paraffin
  • Diffuse dermatitis
  • H/O: non-drug allergy
  • Severe dermatitis, multiple allergies, metabolic wasting syndrome

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • History
      • personal (of)
        • allergy (to)
          • specified NEC

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

Allergy

An allergy is a reaction by your immune system to something that does not bother most other people. People who have allergies often are sensitive to more than one thing. Substances that often cause reactions are:

Read the full article at MedlinePlus

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

Convert Z91.09 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
V15.09 Hx-allergy NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Z91.09Overview

Is Z91.09 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report other allergy status, other than to drugs and biological substances on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z91.09 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because other allergy status, other than to drugs and biological substances describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z91.09 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 other allergy status, other than to drugs and biological substances on inpatient claims.

What is the ICD-9 equivalent of Z91.09?

Under the General Equivalence Mappings, other allergy status, other than to drugs and biological substances converts to ICD-9-CM V15.09 (hx-allergy NEC). The mapping is approximate, so confirm the match fits the documentation.