ICD-10-CM Code Q99.9

Chromosomal abnormality, unspecified

Version 2020 Billable Code POA Exempt

Valid for Submission

Q99.9 is a billable code used to specify a medical diagnosis of chromosomal abnormality, unspecified. The code is valid for the year 2020 for the submission of HIPAA-covered transactions. The ICD-10-CM code Q99.9 might also be used to specify conditions or terms like acute myeloid leukemia due to recurrent genetic abnormality, alpha-thalassemia intellectual disability syndrome linked to chromosome 16, anomaly of chromosome pair 1, anomaly of chromosome pair 10, anomaly of chromosome pair 11, anomaly of chromosome pair 12, etc The code is exempt from present on admission (POA) reporting for inpatient admissions to general acute care hospitals.

Short Description:Chromosomal abnormality, unspecified
Long Description:Chromosomal abnormality, unspecified

Index to Diseases and Injuries

The Index to Diseases and Injuries is an alphabetical listing of medical terms, with each term mapped to one or more ICD-10 code(s). The following references for the code Q99.9 are found in the index:


The following clinical terms are approximate synonyms or lay terms that might be used to identify the correct diagnosis code:

  • Acute myeloid leukemia due to recurrent genetic abnormality
  • Alpha-thalassemia intellectual disability syndrome linked to chromosome 16
  • Anomaly of chromosome pair 1
  • Anomaly of chromosome pair 10
  • Anomaly of chromosome pair 11
  • Anomaly of chromosome pair 12
  • Anomaly of chromosome pair 13
  • Anomaly of chromosome pair 14
  • Anomaly of chromosome pair 15
  • Anomaly of chromosome pair 16
  • Anomaly of chromosome pair 17
  • Anomaly of chromosome pair 18
  • Anomaly of chromosome pair 19
  • Anomaly of chromosome pair 2
  • Anomaly of chromosome pair 20
  • Anomaly of chromosome pair 21
  • Anomaly of chromosome pair 22
  • Anomaly of chromosome pair 3
  • Anomaly of chromosome pair 4
  • Anomaly of chromosome pair 5
  • Anomaly of chromosome pair 6
  • Anomaly of chromosome pair 7
  • Anomaly of chromosome pair 8
  • Anomaly of chromosome pair 9
  • Autosomal chromosomal disorder
  • Autosomal dominant hereditary disorder
  • Autosomal hereditary disorder
  • Autosomal recessive hereditary disorder
  • Autosomal translocation
  • Cardiac arrhythmia associated with genetic disorder
  • Chromosomal disorder
  • Congenital chromosomal disease
  • Deletion of part of chromosome 16
  • Deletion of part of short arm of chromosome 16
  • Dementia due to chromosomal anomaly
  • Dominant autosomal hereditary disorder, complete penetrance
  • Dominant autosomal hereditary disorder, incomplete penetrance
  • Immunodeficiency associated with chromosomal abnormality
  • Ulnar mammary syndrome

Clinical Information

  • CHROMOSOME ABERRATIONS-. abnormal number or structure of chromosomes. chromosome aberrations may result in chromosome disorders.

Present on Admission (POA)

Q99.9 is exempt from POA reporting - The Present on Admission (POA) indicator is used for diagnosis codes included in claims involving inpatient admissions to general acute care hospitals. POA indicators must be reported to CMS on each claim to facilitate the grouping of diagnoses codes into the proper Diagnostic Related Groups (DRG). CMS publishes a listing of specific diagnosis codes that are exempt from the POA reporting requirement. Review other POA exempt codes here .

CMS POA Indicator Options and Definitions
POA Indicator CodePOA Reason for CodeCMS will pay the CC/MCC DRG?
YDiagnosis was present at time of inpatient admission.YES
NDiagnosis was not present at time of inpatient admission.NO
UDocumentation insufficient to determine if the condition was present at the time of inpatient admission.NO
WClinically undetermined - unable to clinically determine whether the condition was present at the time of inpatient admission.YES
1Unreported/Not used - Exempt from POA reporting. NO

Convert Q99.9 to ICD-9

  • 758.9 - Chromosome anomaly NOS

Code Classification

  • Congenital malformations, deformations and chromosomal abnormalities (Q00-Q99)
    • Chromosomal abnormalities, not elsewhere classified (Q90-Q99)
      • Other chromosome abnormalities, not elsewhere classified (Q99)

Code History

  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016
    (First year ICD-10-CM implemented into the HIPAA code set)
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020

Information for Patients

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:

  • Single-gene disorders, where a mutation affects one gene. Sickle cell anemia is an example.
  • Chromosomal disorders, where chromosomes (or parts of chromosomes) are missing or changed. Chromosomes are the structures that hold our genes. Down syndrome is a chromosomal disorder.
  • Complex disorders, where there are mutations in two or more genes. Often your lifestyle and environment also play a role. Colon cancer is an example.

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

NIH: National Library of Medicine

[Learn More]