Q91
Trisomy 18 and Trisomy 13
Q91 is a non-billable ICD-10-CM code category for trisomy 18 and Trisomy 13. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are Q91.0 Trisomy 18, nonmosaicism (meiotic nondisjunction); Q91.1 Trisomy 18, mosaicism (mitotic nondisjunction); Q91.2 Trisomy 18, translocation; Q91.3 Trisomy 18, unspecified and 4 more. Its coding notes include 2 Excludes2 entries.
Guidelines tip
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
Chapter 17 codes can be used for life. Manifestations that are an inherent part of a specifically coded anomaly are not coded separately. A corrected malformation is reported with a personal history code.
Excludes2
Not included here. Both codes may be reported if the patient has both conditions.
Also from chapter/block level (2 notes)
- mitochondrial metabolic disorders (E88.4-)
- inborn errors of metabolism (E70-E88)
Notes
Also from chapter/block level (1 note)
- Codes from this chapter are not for use on maternal records
More specific codes under Q91 8
- 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