Z88.9 Allergy status to unspecified drugs, medicaments and biological substances

The ICD-10-CM code for Allergy status to unspecified drugs, medicaments and biological substances is Z88.9 (FY2026). It is a billable, claim-ready diagnosis code.

Classification

Chapter

21: Factors influencing health status and contact with health services (Z00-Z99)

Section

Z77-Z99: Persons with potential health hazards related to family and personal history and certain conditions influencing health status (Z77-Z99)

Category Z88

11 codes (10 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to Z88.9:

• History › personal (of) › allergy (to)
• History › personal (of) › allergy (to) › medicinal agents
• History › personal (of) › allergy (to) › drugs, medicaments and biological substances

U.S. Hospital Utilization

• An estimated 10,560 U.S. inpatient stays in 2023 included Z88.9 among the documented diagnoses.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Official Coding Guidelines

Z88 category exception for Z88.9

Z88 Allergy status to drugs, medicaments and biological substances Except: Z88.9, Allergy status to unspecified drugs, medicaments and biological substances status

Nonspecific Z Codes—limit inpatient/outpatient use

14) Nonspecific Z Codes Certain Z codes are so non-specific, or potentially redundant with other codes in the classification, that there can be little justification for their use in the inpatient setting. Their use in the outpatient setting should be limited to those instances when there is no further documentation to permit more precise coding. Otherwise, any sign or symptom or any other reason for visit that is captured in another code should be used. Nonspecific Z codes/categories: Z02.9 Encounter for administrative examinations, unspecified Z04.9 Encounter for examination and observation for unspecified reason Z13.9 Encounter for screening, unspecified Z41.9 Encounter for procedure for purposes other than remedying health state, unspecified Z52.9 Donor of unspecified organ or tissue Z86.59 Personal history of other mental and behavioral disorders Z88.9 Allergy status to unspecified drugs, medicaments and biological substances status Z92.0 Personal history of contraception

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)