Q90.9

Down syndrome, unspecified

Billable code

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

This code · Q90.9

Synonyms

Trisomy 21 NOS

Inherited from Q90Down syndrome

Use additional

code(s) to identify any associated degree of intellectual disabilities (F70-F79)

Code also

associated physical condition(s), such as atrioventricular septal defect (Q21.2-)

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

Sections that reference Q90.9

Sections whose FY 2026 text names Q90.9, its Q90 category, or a range containing it — the chapter guidance above is the authoritative source.

4 index paths lead to this code