DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Category · FY2027

Q90 Down syndrome

  • Header · not billable

Q90 is not billable. The category heads 4 billable codes in FY2027: the 4 codes directly below it.

Index → code

  • Down syndrome → Q90.9
  • SyndromeDown → Q90.9
  • Down syndromemosaicism → Q90.1

Where it sits

  1. Chapter 17 Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders (Q00-QA1)
  2. Q90-Q99 Chromosomal abnormalities, not elsewhere classified (Q90-Q99)
  3. Q90 Down syndrome
Billable codes
4
Subdivisions
4
CC / MCC codes
0 / 0
HCC V28 codes
0
New FY2027
0
Index entries
18

Codes in Q90

  1. Q90.0
    Trisomy 21, nonmosaicism (meiotic nondisjunction)
    BillableExempt
  2. Q90.1
    Trisomy 21, mosaicism (mitotic nondisjunction)
    BillableExempt
  3. Q90.2
    Trisomy 21, translocation
    BillableExempt
  4. Q90.9
    Down syndrome, unspecified
    BillableExempt
    Inclusion terms 1

    Inclusion terms

    • Trisomy 21 NOS

Sources of each column.

Instructions

At Q90

Use additional code

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

Code also

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

Notes that also apply

Block Q90-Q99 instructions (Excludes2 1): printed on the block page.

Chapter 17 instructions (Notes 1, Excludes2 1): printed on the chapter 17 page.

Index entries

  • Down syndrome → Q90.9
  • Down syndromemeiotic nondisjunction → Q90.0
  • Down syndromemitotic nondisjunction → Q90.1
  • Down syndromemosaicism → Q90.1
  • Down syndrometranslocation → Q90.2
  • TranslocationDown syndrome → Q90.2
  • SyndromeDown → Q90.9
  • Trisomy (syndrome)21 (partial) → Q90.9
  • Trisomy (syndrome)21 (partial)meiotic nondisjunction → Q90.0
  • Trisomy (syndrome)21 (partial)mitotic nondisjunction → Q90.1
  • Trisomy (syndrome)21 (partial)mosaicism → Q90.1
  • Translocationtrisomy21 → Q90.2
  • Trisomy (syndrome)21 (partial)translocation → Q90.2
  • Syndrometrisomy21 → Q90.9
  • Syndrometrisomy21meiotic nondisjunction → Q90.0
  • Syndrometrisomy21mitotic nondisjunction → Q90.1
  • Syndrometrisomy21mosaicism → Q90.1
  • Syndrometrisomy21translocation → Q90.2

NCHS Alphabetic Index. Index first, then the Tabular List.

Hierarchy