2026 ICD-10-CM Diagnosis Code Q99.0Chimera 46, XX/46, XY

ICD-10-CM Codes›Q00-Q99›Q90-Q99›Q99

ICD-10-CM Q99.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Q99.0 is a billable ICD-10-CM diagnosis code for chimera 46, XX/46, XY. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 729 through 730, 742 through 743, 760 through 761. The code is exempt from POA reporting. Coders also document this condition as chimera. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Chromosomal abnormalities.

Code Identity

ICD-10-CM Code
Q99.0
Billable Status
Yes — Valid for Submission
Code Describes
Chimera 46, XX/46, XY
Short Description
Chimera 46, XX/46, XY
Same as the full description in the CMS dataset.
Parent Code
Q99
Other chromosome abnormalities, not elsewhere classified

Code Classification

ChapterQ00-Q99Congenital malformations, deformations and chromosomal abnormalities
SectionQ90-Q99Chromosomal abnormalities, not elsewhere classified
CategoryQ99Other chromosome abnormalities, not elsewhere classified
This CodeQ99.0Chimera 46, XX/46, XY

Present on Admission (POA)Billing

Q99.0 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Chimera
  • Chimera 46, XX; 46, XY

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Chimera 46, XX/46, XY true hermaphrodite

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Chimera 46,XX/46,XY
    • Hermaphrodite, hermaphroditism(true)
      • 46,XX/46,XY
    • Hermaphrodite, hermaphroditism(true)
      • chimera 46,XX/46,XY

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR MAL009
Chromosomal abnormalities
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Chimera

    an individual that contains cell populations derived from different zygotes.

  • Proteolysis Targeting Chimera

    bifunctional molecules that are designed to recruit e3 ubiquitin ligase to a specific target protein. proteolysis targeting chimera consist of a target protein ligand connected via a linker to an e3 ligand. they promote association of e3 with specific target proteins tagged for degradation via the proteasome.

  • Radiation Chimera

    an organism whose body contains cell populations of different genotypes as a result of the transplantation of donor cells after sufficient ionizing radiation to destroy the mature recipient's cells which would otherwise reject the donor cells.

  • Transplantation Chimera

    an organism that, as a result of transplantation of donor tissue or cells, consists of two or more cell lines descended from at least two zygotes. this state may result in the induction of donor-specific transplantation tolerance.

  • Transplantation

    transference of a tissue or organ from either an alive or deceased donor, within an individual, between individuals of the same species, or between individuals of different species.

  • Transplantation Tolerance

    an induced state of non-reactivity to grafted tissue from a donor organism that would ordinarily trigger a cell-mediated or humoral immune response.

Patient EducationClinical

Genetic Disorders

Genetic disorders are health conditions caused by changes (also called mutations or variants) in your genes. Genes are parts of DNA found in your cells that carry instructions for how your body grows, develops, and functions. Many genes tell your body how to make proteins, which are needed for your body to work properly.

The full article covers:

  • What are genetic disorders?
  • What causes genetic disorders?
  • What are the types of genetic disorders?
  • What are the different ways a genetic disorder can be inherited?
  • How are genetic disorders diagnosed?

Read the full article at MedlinePlus

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

Convert Q99.0 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
758.81 Oth cond due to sex chrm
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Q99.0Overview

Is Q99.0 (Other chromosome abnormalities, not elsewhere classified) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report chimera 46, XX/46, XY on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does Q99.0 group to?

When chimera 46, XX/46, XY is the principal diagnosis on an inpatient stay, it groups to MS-DRG 729, 730, 742, 743, 760, 761, with relative weights from 0.5696 to 1.8348 depending on complications. Higher weights mean higher Medicare reimbursement.

Is Q99.0 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for chimera 46, XX/46, XY on inpatient claims.

What is the ICD-9 equivalent of Q99.0?

Under the General Equivalence Mappings, chimera 46, XX/46, XY converts to ICD-9-CM 758.81 (oth cond due to sex chrm). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.