Q91
Trisomy 18 and Trisomy 13
Header / non-billable
Choose the additional character
Q91 needs more characters to be billable. Pick the specific code below.
- Q91.0Trisomy 18, nonmosaicism (meiotic nondisjunction)Billable
- Q91.1Trisomy 18, mosaicism (mitotic nondisjunction)Billable
- Q91.2Trisomy 18, translocationBillable
- Q91.3Trisomy 18, unspecifiedBillable
- Q91.4Trisomy 13, nonmosaicism (meiotic nondisjunction)Billable
- Q91.5Trisomy 13, mosaicism (mitotic nondisjunction)Billable
- Q91.6Trisomy 13, translocationBillable
- Q91.7Trisomy 13, unspecifiedBillable
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 Q91
FY 2026 ›Sections that reference Q91
Sections whose FY 2026 text names Q91, its Q91 category, or a range containing it — the chapter guidance above is the authoritative source.