ICD-10 Code for Trisomy
Also indexed as (syndrome)
The ICD-10-CM code for trisomy is Q92.9 — Trisomy and partial trisomy of autosomes, unspecified. This is the code the Alphabetic Index gives for trisomy with no further qualifier, valid for FY2027 (October 1, 2026 – September 30, 2027).
Q92.9 is billable but unspecified. If the documentation names a type, site or cause, one of the more specific codes below is likely expected.
Which trisomy code should you use?
The Alphabetic Index lists 18 codes under Trisomy. Which one applies depends on the qualifier documented in the record — the type, site, cause, or associated condition. Find the qualifier below, then verify the code in the Tabular List before using it.
By type
| autosomes | Q92.9 | Trisomy and partial trisomy of autosomes, unspecified | |
| chromosome specified NEC | Q92.8 | Other specified trisomies and partial trisomies of autosomes | |
| specified NEC | Q92.8 | Other specified trisomies and partial trisomies of autosomes | |
| whole chromosome | Q92.9 | Trisomy and partial trisomy of autosomes, unspecified | |
| 13 | Q91.7 | Trisomy 13, unspecified | |
| 18 | Q91.3 | Trisomy 18, unspecified | |
| 20 | Q92.8 | Other specified trisomies and partial trisomies of autosomes | |
| 21 | Q90.9 | Down syndrome, unspecified | |
| 22 | Q92.8 | Other specified trisomies and partial trisomies of autosomes |
Trisomy chromosome specified NEC
| partial | Q92.2 | Partial trisomy | |
| specified NEC | Q92.8 | Other specified trisomies and partial trisomies of autosomes | |
| partial › due to unbalanced translocation | Q92.5 | Duplications with other complex rearrangements | |
| whole › meiotic nondisjunction | Q92.0 | Whole chromosome trisomy, nonmosaicism (meiotic nondisjunction) | |
| whole › mitotic nondisjunction | Q92.1 | Whole chromosome trisomy, mosaicism (mitotic nondisjunction) | |
| whole › mosaicism | Q92.1 | Whole chromosome trisomy, mosaicism (mitotic nondisjunction) |
Trisomy whole chromosome
| meiotic nondisjunction | Q92.0 | Whole chromosome trisomy, nonmosaicism (meiotic nondisjunction) | |
| mitotic nondisjunction | Q92.1 | Whole chromosome trisomy, mosaicism (mitotic nondisjunction) | |
| mosaicism | Q92.1 | Whole chromosome trisomy, mosaicism (mitotic nondisjunction) | |
| partial | Q92.9 | Trisomy and partial trisomy of autosomes, unspecified | |
| specified NEC | Q92.8 | Other specified trisomies and partial trisomies of autosomes |
Trisomy 13
Trisomy 18
Index terms and codes are reproduced from the official ICD-10-CM FY2027 release. The Alphabetic Index is a finding aid — a code must always be verified in the Tabular List before it is reported. Data sources