Q99.8 — Other specified chromosome abnormalities
Is Q99.8 billable?
No — Q99.8 is a non-billable header code. Q99.8 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 6 billable codes beneath Q99.8.
Q99.8 at a glance
| Code | Q99.8 |
|---|---|
| Description | Other specified chromosome abnormalities |
| Billable | No — header code |
| Code set | ICD-10-CM FY2027 |
| Valid for encounters | October 1, 2026 – September 30, 2027 |
How is Q99.8 listed in the Alphabetic Index?
These are the routes through the Alphabetic Index that lead to Q99.8. They show the wording a clinician may have documented, which often differs from the Tabular description.
- Additional › chromosome
- Translocation › chromosomes NEC
- Abnormal, abnormality, abnormalities › chromosome, chromosomal › sex
- Abnormal, abnormality, abnormalities › chromosome, chromosomal › specified NEC
- Anomaly, anomalous › chromosomes, chromosomal › specified NEC (congenital) (unspecified type)
- Syndrome › due to abnormality › chromosomal › specified NEC
Excludes2 — not included here — inherited from Chapter 17
The conditions below are not part of Q99.8, but a patient may have both at the same time. When documentation supports it, Q99.8 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 Q99.8, but a patient may have both at the same time. When documentation supports it, Q99.8 and the excluded code may both be reported.
- mitochondrial metabolic disorders (E88.4-)
What codes fall under Q99.8? (2)
How long has Q99.8 existed?
Q99.8 has been in ICD-10-CM since at least FY2016, the earliest fiscal year on record here.
- FY2026: Q99.8 stopped being billable
Derived from the official order files for FY2016–FY2026. FY2017 and FY2020 publish no order file, so those years are not covered.