Q99 vs Z15
Q99 (Other chromosome abnormalities, not elsewhere classified) compared with Z15 (Genetic susceptibility to disease), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. Z15 carries an Excludes1 note covering Q99: “chromosomal anomalies (Q90-Q99)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| Q99Other chromosome abnormalities, not elsewhere classified | Z15Genetic susceptibility to disease | |
|---|---|---|
| Billing status | Non-billable header | Non-billable header |
| Classification | Q00-Q99 — Congenital Malformations, Deformations and Chromosomal Abnormalities (Q00-Q99) | Z00-Z99 — Factors Influencing Health Status and Contact with Health Services (Z00-Z99) |
| Definition | Other chromosome abnormalities, not elsewhere classified is a non-billable ICD-10-CM category code (Q99). | Genetic susceptibility to disease is a non-billable ICD-10-CM category code (Z15). |
| Includes | — | confirmed abnormal gene |
| Use additional code | — | code, if applicable, for any associated family history of the disease (Z80-Z84) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources