Trisomy 18 and Trisomy 13 (Q91) ICD-10-CM
The Q91 code range covers trisomy 18 and trisomy 13 with 9 ICD-10-CM diagnosis codes. 8 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
Codes in the Q91 Range 9 codes · 8 billable
- Q91 Trisomy 18 and Trisomy 13Non-billable
- Q91.0 Trisomy 18, nonmosaicism (meiotic nondisjunction)
- Q91.1 Trisomy 18, mosaicism (mitotic nondisjunction)
- Q91.2 Trisomy 18, translocation
- Q91.3 Trisomy 18, unspecified
- Q91.4 Trisomy 13, nonmosaicism (meiotic nondisjunction)
- Q91.5 Trisomy 13, mosaicism (mitotic nondisjunction)
- Q91.6 Trisomy 13, translocation
- Q91.7 Trisomy 13, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the Q91 range.
Complete Trisomy 18 Syndrome
A constellation of symptoms that occur as a result of the presence of a complete third copy of the 18th chromosome. Characteristics include profound mental retardation and severe malformations. Individuals with this syndrome rarely live past one year.
About the Q91 Code Range
The codes follow parallel patterns for abnormalities involving chromosome 18 and chromosome 13. Within each group, they distinguish nonmosaicism, mosaicism, translocation, and unspecified forms.
For chromosome 18, Q91.0 identifies nonmosaicism, Q91.1 mosaicism, Q91.2 translocation, and Q91.3 an unspecified form. For chromosome 13, Q91.4 identifies nonmosaicism, Q91.5 mosaicism, Q91.6 translocation, and Q91.7 an unspecified form.
Questions About This Page
How many billable codes are in the Q91 range?
Of the 9 codes in this range, 8 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the Q91 range classify?
The range classifies trisomy 18 and trisomy 13. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
