Q99
Other chromosome abnormalities, not elsewhere classified
Header / non-billable
Choose the additional character
Q99 needs more characters to be billable. Pick the specific code below.
This code does not map to a risk-adjusting HCC in the loaded models.
Coding notes
Excludes 1 never coded together · Excludes 2 may co-exist
Inherited from Q90-Q99Chromosomal abnormalities, not elsewhere classified
Excludes 2
mitochondrial metabolic disorders (E88.4-)
Inherited from chapter 17Congenital malformations, deformations and chromosomal abnormalities
Excludes 2
inborn errors of metabolism (E70-E88)
Note
Codes from this chapter are not for use on maternal records
Official Guidelines for Q99
FY 2026 ›Sections that reference Q99
Sections whose FY 2026 text names Q99, its Q99 category, or a range containing it — the chapter guidance above is the authoritative source.