2026 ICD-10-CM Diagnosis Code Z15.1Genetic susceptibility to epilepsy and neurodevelopmental disorders

ICD-10-CM Codes›Z00–Z99›Z14-Z15›Z15

ICD-10-CM Z15.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z15.1 is a billable ICD-10-CM diagnosis code for genetic susceptibility to epilepsy and neurodevelopmental disorders. 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 Genetic susceptibility to disease.

Code Identity

ICD-10-CM Code
Z15.1
Billable Status
Yes — Valid for Submission
Code Describes
Genetic susceptibility to epilepsy and neurodevelopmental disorders
Short Description
Genetic susceptibility to epi and neurodevelopmental disord
Parent Code
Z15
Genetic susceptibility to disease

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ14-Z15Genetic carrier and genetic susceptibility to disease
CategoryZ15Genetic susceptibility to disease
This CodeZ15.1Genetic susceptibility to epilepsy and neurodevelopmental disorders

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z15.1.

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

Z15.1 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.

Code Also

  • , if applicable, related disorders such as:
  • developmental and epileptic encephalopathy G93.45
  • developmental disorder of speech and language F80
  • developmental disorders of scholastic skills F81
  • epilepsy, by specific type G40
  • intellectual disabilities F70 F79
  • other neurodevelopmental disorder F88
  • pervasive developmental disorders F84

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.

    • Genetic
      • susceptibility to disease NEC
        • epilepsy
    • Genetic
      • susceptibility to disease NEC
        • neurodevelopmental disorders

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR FAC029
Genetic susceptibility to disease
Default principal diagnosis: inpatient No · outpatient No

Code History & ChangesHistory

Replacement Z15.1 replaces the following previously assigned code(s):

  • Z15.89 - Genetic susceptibility to other disease
FY 2025AddedAdded to the ICD-10-CM code setEffective October 1, 2024.
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Z15.1Overview

Is Z15.1 (Genetic susceptibility to disease) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report genetic susceptibility to epilepsy and neurodevelopmental disorders on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z15.1 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because genetic susceptibility to epilepsy and neurodevelopmental disorders describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z15.1 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 genetic susceptibility to epilepsy and neurodevelopmental disorders on inpatient claims.