ICD-10-CM · FY 2026 APRIL UPDATE
Q99
Other chromosome abnormalities, not elsewhere classified
Diagnosis reference
Nonbillable categoryThis entry is a category or subcategory. Choose the appropriate billable descendant based on the clinical documentation.
Effective periodOctober 1, 2026–September 30, 2027
SourceCMS ICD-10-CM order file
ClassificationDiagnosis · clinical modification
Related entries
Up to 30 descendants in this category
| CODE | DESCRIPTION | TYPE |
|---|---|---|
| Q99.0 | Chimera 46, XX/46, XY | Billable |
| Q99.1 | 46, XX true hermaphrodite | Billable |
| Q99.2 | Fragile X chromosome | Billable |
| Q99.8 | Other specified chromosome abnormalities | Category |
| Q99.81 | Usher syndrome | Category |
| Q99.811 | Usher syndrome, type 1 | Billable |
| Q99.812 | Usher syndrome, type 2 | Billable |
| Q99.813 | Usher syndrome, type 3 | Billable |
| Q99.818 | Other Usher syndrome | Billable |
| Q99.819 | Usher syndrome, unspecified | Billable |
| Q99.89 | Other specified chromosome abnormalities | Billable |
| Q99.9 | Chromosomal abnormality, unspecified | Billable |
Use the complete reference
This reference does not reproduce the full tabular hierarchy, inclusion notes, Excludes1/2 notes, sequencing instructions, or seventh-character rules. Review the official tables and coding guidelines.
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