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v1.0.0
ICD-10 Guide
ICD-10 CodesQ21.20

Q21.20

Billable

Atrioventricular septal defect, unspecified as to partial or complete

BILLABLE STATUSYes
IMPLEMENTATION DATEOctober 1, 2015
LAST UPDATED09/11/2025

Code Description

ICD-10 Q21.20 is a billable code used to indicate a diagnosis of atrioventricular septal defect, unspecified as to partial or complete.

Key Diagnostic Point:

Atrioventricular septal defect (AVSD) is a congenital heart defect characterized by a combination of atrial septal defect (ASD) and ventricular septal defect (VSD), leading to a single common atrioventricular valve instead of separate mitral and tricuspid valves. This condition results in abnormal blood flow between the heart chambers, causing increased pulmonary blood flow and potential heart failure if not treated. AVSD can be classified into two types: complete and partial, but when unspecified, it indicates that the exact nature of the defect is not determined. Symptoms may include difficulty breathing, poor feeding, and failure to thrive in infants. Diagnosis is typically made through echocardiography, which visualizes the heart's structure and function. Management often requires surgical intervention to repair the defect and restore normal hemodynamics, with follow-up care essential for monitoring potential complications such as arrhythmias or pulmonary hypertension.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Differentiating between complete and partial AVSD when unspecified.
  • Understanding associated congenital anomalies that may complicate coding.
  • Variability in clinical presentation and severity among patients.
  • Need for precise documentation from cardiologists regarding the defect's nature.

Audit Risk Factors

  • Inadequate documentation of the defect's type (complete vs. partial).
  • Failure to capture associated congenital anomalies.
  • Misinterpretation of echocardiographic findings.
  • Inconsistent coding practices across different healthcare providers.

Specialty Focus

Medical Specialties

Pediatrics

Documentation Requirements

Detailed clinical notes on symptoms, diagnostic imaging results, and treatment plans.

Common Clinical Scenarios

Infants presenting with failure to thrive, respiratory distress, or heart murmurs.

Billing Considerations

Pediatric patients may require ongoing monitoring for growth and development post-repair.

Genetics

Documentation Requirements

Family history of congenital heart defects and genetic testing results if applicable.

Common Clinical Scenarios

Patients with syndromic presentations such as Down syndrome, which is commonly associated with AVSD.

Billing Considerations

Genetic counseling may be necessary for families with a history of congenital anomalies.

Coding Guidelines

Inclusion Criteria

Use Q21.20 When
  • Follow the official ICD
  • CM coding guidelines for congenital malformations, ensuring accurate documentation of the defect's nature and any associated conditions
  • Use additional codes to capture related anomalies or complications

Exclusion Criteria

Do NOT use Q21.20 When
No specific exclusions found.

Related ICD-10 Codes

Related CPT Codes

33533CPT Code

Repair of atrioventricular septal defect

Clinical Scenario

Used during surgical intervention for AVSD.

Documentation Requirements

Operative reports detailing the surgical approach and findings.

Specialty Considerations

Pediatric cardiology should provide detailed surgical notes.

ICD-10 Impact

Diagnostic & Documentation Impact

Enhanced Specificity

ICD-10 Improvements

The transition to ICD-10 has allowed for more specific coding of congenital heart defects, improving data accuracy and facilitating better patient management.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of congenital heart defects, improving data accuracy and facilitating better patient management.

Reimbursement & Billing Impact

The transition to ICD-10 has allowed for more specific coding of congenital heart defects, improving data accuracy and facilitating better patient management.

Resources

Clinical References

  • •
    American Academy of Pediatrics - Congenital Heart Disease

Coding & Billing References

  • •
    American Academy of Pediatrics - Congenital Heart Disease

Frequently Asked Questions

What is the difference between complete and partial AVSD?

Complete AVSD involves a single common atrioventricular valve with both atrial and ventricular septal defects, while partial AVSD has a separate mitral valve but still includes a ventricular septal defect. Accurate coding requires understanding these distinctions.