Q90-Q99
Medium Complexity
Chromosomal abnormalities, not elsewhere classified
Primary Specialty: Genetics
Last Updated: 2025-09-10
ICD-10 Codes (76)
67 billable2 category headers
Q91Q91.0Billable
Q91.1Billable
Q91.2Billable
Q91.3Billable
Q91.4Billable
Q91.5Billable
Q91.6Billable
Q91.7Billable
Q92Billable
Q92.0Billable
Q92.1Billable
Q92.2Billable
Q92.5Billable
Q92.6Billable
Q92.61Billable
Q92.62Billable
Q92.7Billable
Q92.8Billable
Q92.9Billable
Q93Q93.0Billable
Q93.1Billable
Q93.2Billable
Q93.3Billable
Q93.4Billable
Q93.5Q93.51Billable
Q93.52Billable
Q93.59Billable
Q93.7Billable
Q93.8Q93.81Billable
Q93.82Billable
Q93.88Billable
Q93.89Billable
Q93.9Billable
Q95Q95.0Billable
Q95.1Billable
Q95.2Billable
Q95.3Billable
Q95.5Billable
Q95.8Billable
Q95.9Billable
Q96Q96.0Billable
Q96.1Billable
Q96.2Billable
Q96.3Billable
Q96.4Billable
Q96.8Billable
Q96.9Billable
Q97Q97.0Billable
Q97.1Billable
Q97.2Billable
Q97.3Billable
Q97.8Billable
Q97.9Billable
Q98Q98.0Billable
Q98.1Billable
Q98.3Billable
Q98.4Billable
Q98.5Billable
Q98.6Billable
Q98.7Billable
Q98.8Billable
Q98.9Billable
Q99Q99.0Billable
Q99.1Billable
Q99.2Billable
Q99.8Billable
Q99.9Billable
Updates & Changes
FY 2026 Updates
Current Year
New Codes (1)
Q23.4
Hypoplastic left heart syndrome with mitral atresia
Revised Codes (1)
Q21.0
Ventricular septal defect - updated to include hemodynamic significance when known
Deleted Codes
No codes deleted in this range for FY 2026
Historical Changes
- •FY 2025: Routine maintenance updates with minor terminology clarifications
- •FY 2024: Enhanced specificity requirements for certain code ranges
- •FY 2023: Updated documentation guidelines for improved clarity
Upcoming Changes
- •Proposed updates pending review by Coordination and Maintenance Committee
- •Under consideration: Enhanced digital health integration codes
Implementation Guidance
- •Review all FY 2026 updates for Q90-Q99 codes before implementation
- •Always verify the most current codes in the ICD-10-CM manual
- •Ensure clinical documentation supports the selected diagnosis codes
- +3 more guidance items...
Range Overview
high priority
The ICD-10 code range Q90-Q99 is dedicated to chromosomal abnormalities that are not classified elsewhere. These codes cover a broad spectrum of genetic disorders, from Down syndrome (Q90) to other chromosomal abnormalities, not elsewhere classified (Q99). These codes are used to document diagnoses related to chromosomal abnormalities, which can manifest as various physical and cognitive impairments, and are often identified through genetic testing.
Key Usage Points:
- •Always code the manifestation of the chromosomal abnormality, if known and applicable.
- •Use additional codes to identify any associated physical or mental disabilities.
- •For congenital malformations, deformations, and chromosomal abnormalities, use codes from Chapter 17 (Q00-Q99).
- •If the patient has a well-documented chromosomal abnormality but no specific manifestations, code the abnormality itself.
- •Always verify the code in the Tabular List before assigning it.
Coding Guidelines
When to Use:
- ✓When a patient has a confirmed diagnosis of a chromosomal abnormality.
- ✓When a patient presents with symptoms or conditions typically associated with a chromosomal abnormality.
- ✓When a patient has undergone genetic testing that confirms a chromosomal abnormality.
- ✓When a patient's family history includes chromosomal abnormalities.
When NOT to Use:
- ✗When the patient's condition is due to an acquired genetic mutation, not a chromosomal abnormality.
- ✗When the patient's condition is better represented by another code.
- ✗When the patient's chromosomal abnormality is not confirmed by genetic testing or clinical diagnosis.
- ✗When the patient's condition is due to an environmental factor, not a chromosomal abnormality.
Code Exclusions
Always verify exclusions in the Tabular List before assigning a code.
Documentation Requirements
Documentation for chromosomal abnormalities should be thorough and precise, including specific diagnoses, manifestations, and results of genetic testing. It should also include the patient's history and any associated conditions.
Clinical Information:
- •Specific diagnosis of the chromosomal abnormality
- •Results of genetic testing
- •Manifestations of the chromosomal abnormality
- •Patient's history and associated conditions
- •Any physical or mental disabilities associated with the abnormality
Supporting Evidence:
- •Genetic test results
- •Clinical notes
- •Imaging studies
- •Laboratory test results
Good Documentation Example:
Patient diagnosed with Down syndrome (Q90.9) with moderate intellectual disabilities (F71). Genetic testing confirmed trisomy 21.
Poor Documentation Example:
Patient has Down syndrome.
Common Documentation Errors:
- âš Not specifying the type of chromosomal abnormality
- âš Not documenting associated conditions or disabilities
- âš Not including results of genetic testing
- âš Not verifying the code in the Tabular List
Range Statistics
9
Total Codes
67
Billable
Complexity:
Medium
Primary Use:Clinical Documentation
Chapter:17
Coding Complexity
Medium
Complexity Rating
Coding for chromosomal abnormalities requires a solid understanding of genetics and the ability to interpret complex genetic test results. It also requires familiarity with the ICD-10 coding system and the ability to accurately code associated conditions and manifestations.
Key Factors:
- â–¸Knowledge of genetics and chromosomal abnormalities
- â–¸Understanding of associated conditions and manifestations
- â–¸Ability to interpret genetic test results
- â–¸Familiarity with the ICD-10 coding system and guidelines
Specialty Focus
These codes are primarily used by geneticists, pediatricians, and other specialists who diagnose and treat chromosomal abnormalities.
Primary Specialties:
Genetics
40%
Pediatrics
30%
Obstetrics and Gynecology
20%
Clinical Scenarios:
- • A newborn diagnosed with Down syndrome and associated heart defects.
- • A pregnant woman undergoing prenatal testing that reveals a chromosomal abnormality in the fetus.
- • A child with developmental delays diagnosed with a chromosomal abnormality.
- • An adult with a family history of chromosomal abnormalities undergoing genetic testing.
Resources & References
Several resources are available for coding chromosomal abnormalities, including the ICD-10 coding manual, official coding guidelines, and clinical reference materials.
Official Guidelines:
- ICD-10-CM Official Guidelines for Coding and Reporting
- American Health Information Management Association (AHIMA) Coding Guidelines
- Centers for Disease Control and Prevention (CDC) ICD-10 Resources
Clinical References:
- Genetics Home Reference
- National Human Genome Research Institute (NHGRI)
Educational Materials:
- AHIMA ICD-10 Training Materials
- CDC ICD-10 Training Webinars
Frequently Asked Questions
How do I code for a chromosomal abnormality with multiple manifestations?
Use a code for the chromosomal abnormality, and additional codes for each manifestation, if applicable. Always verify the codes in the Tabular List.