ICD10BillableValid for clinical use

ICD-10 Code Z91.0120: Allergy to eggs, unspecified

Z91.0120 is a billable ICD-10 diagnosis code used to classify Allergy to eggs, unspecified in medical records and claims. You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records. ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Factors influencing health status and contact with health services (Z00-Z99).

Reviewed by HealthAssure Clinical TeamUpdated 26 May 2026

What is this code?

ICD-10 codes are diagnosis classification codes used in healthcare records, reporting, coding workflows, and billing support. This code sits within the broader ICD-10 area for Factors influencing health status and contact with health services (Z00-Z99).

When is it used?

  • May be used when a clinician documents allergy to eggs, unspecified in a patient's medical record.
  • May appear in hospital records, claims, referrals, and clinical documentation.
  • This code can be used as a clinically usable diagnosis entry in standardized coding workflows.

What it does not mean

  • A code alone does not explain severity, treatment plan, or outcome.
  • A medical code should not be treated as a substitute for a doctor's diagnosis or advice.

Code hierarchy

chapter
21Factors influencing health status and contact with health services (Z00-Z99)
block
Z77-Z99Persons with potential health hazards related to family and personal history and certain conditions influencing health status
category
Z91Personal risk factors, not elsewhere classified
category
Z91.0Allergy status, other than to drugs and biological substances
category
Z91.01Food allergy status
category
Z91.012Allergy to eggs
currentZ91.012

Where you may see this code

You may see this code in hospital records, discharge summaries, insurance claims, encounter documentation, referrals, or other healthcare billing and coding records.

Related specialists

General Physician

Coverage-related procedures and services

CPT 86005high
ALLERGEN SPECIFIC IGE; QUALITATIVE, MULTIALLERGEN SCREEN (EG, DISK, SPONGE, CARD)
Source: CMS coverage guidance
CPT 86003high
ALLERGEN SPECIFIC IGE; QUANTITATIVE OR SEMIQUANTITATIVE, CRUDE ALLERGEN EXTRACT, EACH
Source: CMS coverage guidance
CPT 86001high
ALLERGEN SPECIFIC IGG QUANTITATIVE OR SEMIQUANTITATIVE, EACH ALLERGEN
Source: CMS coverage guidance
CPT 86008high
ALLERGEN SPECIFIC IGE; QUANTITATIVE OR SEMIQUANTITATIVE, RECOMBINANT OR PURIFIED COMPONENT, EACH
Source: CMS coverage guidance
CPT 95018high
ALLERGY TESTING, ANY COMBINATION OF PERCUTANEOUS (SCRATCH, PUNCTURE, PRICK) AND INTRACUTANEOUS (INTRADERMAL), SEQUENTIAL AND INCREMENTAL, WITH DRUGS OR BIOLOGICALS, IMMEDIATE TYPE REACTION, INCLUDING TEST INTERPRETATION AND REPORT, SPECIFY NUMBER OF TESTS
Source: CMS coverage guidance
CPT 95017high
ALLERGY TESTING, ANY COMBINATION OF PERCUTANEOUS (SCRATCH, PUNCTURE, PRICK) AND INTRACUTANEOUS (INTRADERMAL), SEQUENTIAL AND INCREMENTAL, WITH VENOMS, IMMEDIATE TYPE REACTION, INCLUDING TEST INTERPRETATION AND REPORT, SPECIFY NUMBER OF TESTS
Source: CMS coverage guidance

Coding guidelines

Common synonyms

Allergy to eggs, unspecifiedAllergy to eggs

Frequently asked questions

Code details

CodeZ91.0120
SystemICD10
Display nameAllergy to eggs, unspecified
ChapterFactors influencing health status and contact with health services (Z00-Z99)
BlockPersons with potential health hazards related to family and personal history and certain conditions influencing health status

Flags

BillableYes
Valid clinical useYes

Source

SourceICD-10
Version2026-annual
Releaseannual
Year2026

Index terms

Matched terms
Allergy, allergic(reaction) (to)History

About this content

This page is prepared by HealthAssure's clinical team using official coding standards from ICD-10. AI tools assist with drafting explanations, which are then reviewed and verified by healthcare professionals for accuracy. This content is for informational purposes and does not replace professional medical advice. Meet our team.

ICD-10 Code Z91.0120 for Allergy to eggs, unspecified | HealthAssure