Q99 - Other chromosome abnormalities, not elsewhere classified

Version 2023
ICD-10:Q99
Short Description:Other chromosome abnormalities, not elsewhere classified
Long Description:Other chromosome abnormalities, not elsewhere classified
Status: Not Valid for Submission
Version:ICD-10-CM 2023
Code Classification:
  • Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
    • Chromosomal abnormalities, not elsewhere classified (Q90-Q99)
      • Other chromosome abnormalities, not elsewhere classified (Q99)

Q99 is a non-specific and non-billable ICD-10 code code, consider using a code with a higher level of specificity for a diagnosis of other chromosome abnormalities, not elsewhere classified. The code is not specific and is NOT valid for the year 2023 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding for Other chromosome abnormalities, not elsewhere classified

Non-specific codes like Q99 require more digits to indicate the appropriate level of specificity. Consider using any of the following ICD-10 codes with a higher level of specificity when coding for other chromosome abnormalities, not elsewhere classified:

  • BILLABLE CODE - Use Q99.0 for Chimera 46, XX/46, XY
  • BILLABLE CODE - Use Q99.1 for 46, XX true hermaphrodite
  • BILLABLE CODE - Use Q99.2 for Fragile X chromosome
  • BILLABLE CODE - Use Q99.8 for Other specified chromosome abnormalities
  • BILLABLE CODE - Use Q99.9 for Chromosomal abnormality, unspecified

Patient Education


Genetic Disorders

Genes are the building blocks of heredity. They are passed from parent to child. They hold DNA, the instructions for making proteins. Proteins do most of the work in cells. They move molecules from one place to another, build structures, break down toxins, and do many other maintenance jobs.

Sometimes there is a mutation, a change in a gene or genes. The mutation changes the gene's instructions for making a protein, so the protein does not work properly or is missing entirely. This can cause a medical condition called a genetic disorder.

You can inherit a gene mutation from one or both parents. A mutation can also happen during your lifetime.

There are three types of genetic disorders:

Genetic tests on blood and other tissue can identify genetic disorders.

NIH: National Library of Medicine


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Code History