2026 ICD-10-CM Diagnosis Code Z91.BPersonal risk factor of exposure to diethylstilbestrol

ICD-10-CM Codes›Z00–Z99›Z77-Z99›Z91

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

Z91.B is a billable ICD-10-CM diagnosis code for personal risk factor of exposure to diethylstilbestrol. 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.

Code Identity

ICD-10-CM Code
Z91.B
Billable Status
Yes — Valid for Submission
Code Describes
Personal risk factor of exposure to diethylstilbestrol
Short Description
Personal risk factor of exposure to diethylstilbestrol
Same as the full description in the CMS dataset.
Parent Code
Z91
Personal risk factors, not elsewhere classified

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.BPersonal risk factor of exposure to diethylstilbestrol

Code EditsBilling

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

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

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • DES daughter or son
  • Personal risk factor of exposure to DES
  • Personal risk factor of exposure to DES in utero
  • Second generation DES exposure

Code Also

  • , associated conditions, such as:
  • conditions classifiable to C50
  • osteoporosis M80
  • premature menopause E28.31

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.

    • DES
      • child (daughter) (son)
    • DES
      • second generation
    • Exposure(to)
      • risk factor, personal, to diethylstilbestrol (DES) (in utero)

Code History & ChangesHistory

New Code Z91.B was added to the ICD-10-CM code set for FY 2026, effective October 1, 2025.

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

  • Z91.89 - Oth personal risk factors, not elsewhere classified
FY 2026AddedAdded to the ICD-10-CM code setEffective October 1, 2025.
FY 2026CurrentRevised in the current code setEffective October 1, 2025 through September 30, 2026.

Questions About Z91.BOverview

Is Z91.B (Personal risk factors, not elsewhere classified) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report personal risk factor of exposure to diethylstilbestrol on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z91.B be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because personal risk factor of exposure to diethylstilbestrol describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z91.B 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 personal risk factor of exposure to diethylstilbestrol on inpatient claims.