2027 ICD-10-CM Diagnosis Code Q90Down syndrome

ICD-10-CM Codes›Q00-Q99›Q90-Q99›Q90

ICD-10-CM Q90
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

Q90 is a non-billable ICD-10-CM category code for down syndrome, so it cannot be submitted on claims. Use a more specific code from this category instead, such as Q90.0, Q90.1, Q90.2, and Q90.9.

Code Identity

ICD-10-CM Code
Q90
Billable Status
No — Non-Billable Category
Code Describes
Down syndrome
Short Description
Down syndrome
Same as the full description in the CMS dataset.
Chapter
Q90-Q99
Chromosomal abnormalities, not elsewhere classified

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ90-Q99Chromosomal abnormalities, not elsewhere classified
CategoryQ90Down syndrome
This CodeQ90Down syndrome

Specific Coding for Down syndromeOverview

Non-specific codes like Q90 require more characters. Use one of these billable codes instead:

  • Use Q90.0 for Trisomy 21, nonmosaicism (meiotic nondisjunction)

  • Use Q90.1 for Trisomy 21, mosaicism (mitotic nondisjunction)

  • Use Q90.2 for Trisomy 21, translocation

  • Use Q90.9 for Down syndrome, unspecified

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Q90: its own notes plus those printed at block Q90-Q99 and Chapter 17. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From Block Q90-Q99 Chromosomal abnormalities, not elsewhere classified applies to 74 codes
  • mitochondrial metabolic disorders (E88.4-)
From Chapter 17 (Q00-QA1) Congenital malformations, deformations and chromosomal abnormalities applies to 900 codes
  • inborn errors of metabolism (E70-E88)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

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

Code Also

A second code may be needed to fully describe the condition; the note gives no sequencing direction.

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

Notes

General instructions on how these codes are used.

From Chapter 17 (Q00-QA1) Congenital malformations, deformations and chromosomal abnormalities applies to 900 codes
  • Codes from this chapter are not for use on maternal records

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name Q90, its category, or a range that includes it.

Excludes1 4

These codes carry an Excludes1 note naming Q90: they are not reported together with it, unless the two conditions are unrelated.

  • E25 Adrenogenital disorders
    chromosomal abnormalities (Q90-Q99)
  • Block Q50-Q56 Congenital malformations of genital organs
    syndromes associated with anomalies in the number and form of chromosomes (Q90-Q99)
  • Q92 Other trisomies and partial trisomies of the autosomes, not elsewhere classified
    trisomies of chromosomes 13, 18, 21 (Q90-Q91)
  • Z15 Genetic susceptibility to disease
    chromosomal anomalies (Q90-Q99)

Code First 1

These codes say to code first a condition named in the note, and Q90 is one of the conditions named.

  • D84.81 Immunodeficiency due to conditions classified elsewhere
    chromosomal abnormalities (Q90-Q99)

Clinical InformationClinical

  • Down Syndrome

    a chromosome disorder associated either with an extra chromosome 21 or an effective trisomy for chromosome 21. clinical manifestations include hypotonia, short stature, brachycephaly, upslanting palpebral fissures, epicanthus, brushfield spots on the iris, protruding tongue, small ears, short, broad hands, fifth finger clinodactyly, single transverse palmar crease, and moderate to severe intellectual disability. cardiac and gastrointestinal malformations, a marked increase in the incidence of leukemia, and the early onset of alzheimer disease are also associated with this condition. pathologic features include the development of neurofibrillary tangles in neurons and the deposition of amyloid beta-protein, similar to the pathology of alzheimer disease. (menkes, textbook of child neurology, 5th ed, p213)

Patient EducationClinical

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.

The full article covers:

  • What is Down syndrome?
  • What causes Down syndrome?
  • What are the symptoms of Down syndrome?
  • What other problems does Down syndrome cause?
  • How is Down syndrome diagnosed?
  • What are the treatments for Down syndrome?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About Q90Overview

What is the ICD-10 code for down syndrome?

Q90 is the ICD-10-CM category for down syndrome, but it is a non-billable header: claims need a more specific code from this category, listed on this page.

Is Q90 (Down syndrome) a billable code?

No. This is a category header that groups the codes for down syndrome, and headers cannot be submitted on claims. Claims for down syndrome need a more specific code from this category, such as Q90.0, Q90.1, and Q90.2.

Does Q90 need an additional code?

When the condition applies, yes. The Use Additional Code note reads: code(s) to identify any associated degree of intellectual disabilities (F70-F79). The additional code is reported after Q90.