Q96.1 ICD-10-CM Code: Karyotype 46, X iso (Xq)
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FY 2026 Apr update / Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0) / Chromosomal abnormalities, not elsewhere classified (Q90-Q99)
Q96.1
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceKaryotype 46, X iso (Xq)
A chromosomal condition where a person has 46 chromosomes but one X chromosome is abnormal (isochromosome Xq), affecting sexual development and physical characteristics.
CMS-HCC V28
00
RAF 0
CMS-HCC V24
00
RAF 0
ACA/HHS
00
RAF 0
ESRD/PACE
00
RAF 0
RXHCC
00
RAF 0
Code Trumping
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Code Book Path
Inclusion Terms
Official- Karyotype 46, isochromosome Xq
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for Q96.1 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for Q96.1 in this effective period.
Excludes 1
Official- Noonan syndrome (Q87.19)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for Q96.1 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for Q96.1 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for Q96.1 in this effective period.
Buddy Documentation Tip
Last updated: FY2026 ICD-10-CM Apr update, Apr 1, 2026 through Sep 30, 2026. CMS-HCC V28 is 100% phased in for payment year 2026.
Is Q96.1 an HCC code?
No. Q96.1 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
Q96.1 is the ICD-10-CM diagnosis code for karyotype 46, x iso (xq). A chromosomal condition where a person has 46 chromosomes but one X chromosome is abnormal (isochromosome Xq), affecting sexual development and physical characteristics. Q96.1 sits in the ICD-10-CM chapter for congenital malformations, deformations and chromosomal abnormalities (q00-qa0), within the section covering chromosomal abnormalities, not elsewhere classified (q90-q99).
Q96.1 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
This is a specific karyotype variant of Turner's syndrome; document the genetic test results in the medical record.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for Q96.1 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is a specific karyotype variant of Turner's syndrome; document the genetic test results in the medical record
- •Use this code when genetic testing confirms the isochromosome Xq pattern rather than the unspecified Turner's code