Z91.09Other allergy status, other than to drugs and biological substances

Z91.09 is the ICD-10-CM diagnosis code for other allergy status, other than to drugs and biological substances. It belongs to category Z91 (personal risk factors, not elsewhere classified), block Z77-Z99 (persons with potential health hazards related to family and personal history and certain conditions influencing health status) and chapter 21 (factors influencing health status and contact with health services). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within Z91.0, choose Z91.09 (Other allergy status, other than to drugs and biological substances) only when documentation doesn't support a more specific option: food allergy status (Z91.01), food additives allergy status (Z91.02), insect allergy status (Z91.03) and nonmedicinal substance allergy status (Z91.04).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 951 (Other Factors Influencing Health Status, relative weight 0.5577), in MDC 23 (Factors Influencing Health Status and Other Contacts with Health Services), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.

It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as V15.09 (other allergy, other than to medicinal agents).