ICD-10 Code for Trisomy

The default ICD-10-CM 2027 code for trisomy (syndrome) is Q92.9 – Trisomy and partial trisomy of autosomes, unspecified. More specific codes depend on the details documented, as listed in the official index (18 codes, 18 billable).

Main code: Q92.9 – Trisomy and partial trisomy of autosomes, unspecified
Billable: Yes

Index entries for Trisomy

autosomes – Q92.9
chromosome specified NEC – Q92.8
- partial – Q92.2
  - due to unbalanced translocation – Q92.5
- whole (nonsex chromosome)
  - meiotic nondisjunction – Q92.0
  - mitotic nondisjunction – Q92.1
  - mosaicism – Q92.1
- specified NEC – Q92.8
due to
- dicentrics – see Extra, marker chromosomes
- extra rings – see Extra, marker chromosomes
- isochromosomes – see Extra, marker chromosomes
specified NEC – Q92.8
whole chromosome – Q92.9
- meiotic nondisjunction – Q92.0
- mitotic nondisjunction – Q92.1
- mosaicism – Q92.1
- partial – Q92.9
- specified NEC – Q92.8
13 (partial) – Q91.7
- meiotic nondisjunction – Q91.4
- mitotic nondisjunction – Q91.5
- mosaicism – Q91.5
- translocation – Q91.6
18 (partial) – Q91.3
- meiotic nondisjunction – Q91.0
- mitotic nondisjunction – Q91.1
- mosaicism – Q91.1
- translocation – Q91.2
20 – Q92.8
21 (partial) – Q90.9
- meiotic nondisjunction – Q90.0
- mitotic nondisjunction – Q90.1
- mosaicism – Q90.1
- translocation – Q90.2
22 – Q92.8

How to choose the right code

Start with the main term, then pick the indented subterm that matches the documentation (type, cause, site, laterality, episode of care). Always confirm the code in the tabular list: follow its Excludes1/Excludes2, “code first” and “use additional code” notes, and add a 7th character where required.

Source: CDC/NCHS ICD-10-CM FY2027 alphabetic index.