DxCodebookFY2027 · Oct 1, 2026 – Sep 30, 2027

Block · Chapter 17

Q90-Q99 Chromosomal abnormalities, not elsewhere classified (Q90-Q99)

Block Q90-Q99 groups 9 categories with 74 billable codes in FY2027.

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)

Neighbouring blocks

Categories
9
Billable codes
74
CC codes
23
MCC codes
1
HCC V28 codes
0
New FY2027
0

Categories in Q90-Q99

  • Q90

    Down syndrome

    Down syndrome → Q90.9

    • 4 billable codes
  • Q91

    Trisomy 18 and Trisomy 13

    Trisomy (syndrome)13 (partial) → Q91.7

    • 8 billable codes
    • 8 CC
  • Q92

    Other trisomies and partial trisomies of the autosomes, not elsewhere classified

    Triploidy → Q92.7

    • 9 billable codes
  • Q93

    Monosomies and deletions from the autosomes, not elsewhere classified

    Monosomy → Q93.9

    • 14 billable codes
    • 10 CC
    • 1 MCC
  • Q95

    Balanced rearrangements and structural markers, not elsewhere classified

    Translocationbalanced autosomal → Q95.9

    • 7 billable codes
  • Q96

    Turner's syndrome

    XO syndrome → Q96.9

    • 7 billable codes
  • Q97

    Other sex chromosome abnormalities, female phenotype, not elsewhere classified

    Pentasomy X syndrome → Q97.1

    • 6 billable codes
  • Q98

    Other sex chromosome abnormalities, male phenotype, not elsewhere classified

    XXY syndrome → Q98.0

    • 9 billable codes
  • Q99

    Other chromosome abnormalities, not elsewhere classified

    Swyer syndrome → Q99.1

    • 10 billable codes
    • 5 CC

Index main terms

  • Syndrome → Q90, Q91, Q92, Q93, Q97, Q98, Q99 (53 entries)
  • Trisomy (syndrome) → Q90, Q91, Q92 (33 entries)
  • Abnormal, abnormality, abnormalities → Q93, Q95, Q97, Q98, Q99 (13 entries)
  • Deletion(s) → Q93 (13 entries)
  • Karyotype → Q96, Q97, Q98, Q99 (11 entries)
  • Anomaly, anomalous (congenital) (unspecified type) → Q96, Q97, Q98, Q99 (9 entries)
  • Translocation → Q90, Q91, Q95, Q99 (8 entries)
  • Monosomy → Q93, Q96 (6 entries)
  • Mosaicism, mosaic (autosomal) (chromosomal) → Q96, Q97, Q98 (6 entries)
  • Accessory (congenital) → Q92, Q97 (5 entries)
  • Down syndrome → Q90 (5 entries)
  • Rearrangement → Q95 (5 entries)
  • Hermaphrodite, hermaphroditism (true) → Q99 (4 entries)
  • Fragile, fragility → Q95, Q99 (3 entries)
  • Klinefelter's syndrome → Q98 (3 entries)

+30 more main terms; the search box finds them by word.

Block instructions

Excludes2

  • mitochondrial metabolic disorders (E88.4-) E88.4

Notes that also apply

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