| Q99 | Other chromosome abnormalities, not elsewhere classified | NON-BILLABLE CODE |
| Q99.0 | Chimera 46, XX/46, XY | BILLABLE CODE |
| Q99.1 | 46, XX true hermaphrodite | BILLABLE CODE |
| Q99.2 | Fragile X chromosome | BILLABLE CODE |
| Q99.8 | Other specified chromosome abnormalities | BILLABLE CODE |
