Q90.1

Billable

Trisomy 21, mosaicism (mitotic nondisjunction)

Q90.1 is the ICD-10-CM code for Trisomy 21, mosaicism (mitotic nondisjunction). It is a billable, specific code valid for reimbursement.

Status
Billable
Chapter
Q00-Q99
Parent
Q90
Edition
FY2026

Q00-Q99 Congenital malformations, deformations and chromosomal abnormalities

What this means — in plain language

MedlinePlus · NIH

What is Down syndrome? Down syndrome is a condition in which a person has an extra chromosome or an extra piece of a chromosome. This extra copy changes how a baby's body and brain develop. It can cause both mental and physical challenges during their lifetime. Even though people with Down syndrome might act and look similar, each person has different abilities. What causes Down syndrome? Chromosomes are tiny…

Read more about Down Syndrome at MedlinePlus ↗

Source: U.S. National Library of Medicine (MedlinePlus). Informational only — not medical advice.

No additional coding notes for this code.

Frequently asked questions

What is ICD-10 code Q90.1?
Q90.1 is the ICD-10-CM code for "Trisomy 21, mosaicism (mitotic nondisjunction)". It falls under Q00-Q99 Congenital malformations, deformations and chromosomal abnormalities.
Is Q90.1 a billable code?
Yes — Q90.1 is a billable, specific ICD-10-CM code valid for reimbursement.

Source: CMS ICD-10-CM FY2026. For informational purposes only — not medical advice. See our medical disclaimer.

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