Q99 — Other chromosome abnormalities, not elsewhere classified
Is Q99 billable?
No — Q99 is a non-billable header code. Q99 groups more specific codes and cannot be submitted on a claim. A valid ICD-10-CM code must be reported at the highest level of specificity available in its branch. Select one of the 10 billable codes beneath Q99.
Billable codes under this header
- Q99.0Chimera 46, XX/46, XY
- Q99.146, XX true hermaphrodite
- Q99.2Fragile X chromosome
- Q99.9Chromosomal abnormality, unspecified
- Q99.89Other specified chromosome abnormalities
- Q99.811Usher syndrome, type 1
- Q99.812Usher syndrome, type 2
- Q99.813Usher syndrome, type 3
- Q99.818Other Usher syndrome
- Q99.819Usher syndrome, unspecified
Q99 at a glance
| Code | Q99 |
|---|---|
| Description | Other chromosome abnormalities, not elsewhere classified |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
Excludes2 — not included here — inherited from Chapter 17
The conditions below are not part of Q99, but a patient may have both at the same time. When documentation supports it, Q99 and the excluded code may both be reported.
- inborn errors of metabolism (E70-E88)
Excludes2 — not included here — inherited from Q90-Q99
The conditions below are not part of Q99, but a patient may have both at the same time. When documentation supports it, Q99 and the excluded code may both be reported.
- mitochondrial metabolic disorders (E88.4-)
What codes fall under Q99? (5)
How long has Q99 existed?
Q99 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.