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ICD-10 Guide
ICD-10 CodesQ21.21

Q21.21

Billable

Partial atrioventricular septal defect

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

Code Description

ICD-10 Q21.21 is a billable code used to indicate a diagnosis of partial atrioventricular septal defect.

Key Diagnostic Point:

Partial atrioventricular septal defect (AVSD) is a congenital heart defect characterized by a combination of atrial septal defect (ASD) and ventricular septal defect (VSD) with a single common atrioventricular valve. This condition results in abnormal blood flow between the heart chambers, leading to increased pulmonary blood flow and potential heart failure if left untreated. Patients may present with symptoms such as cyanosis, fatigue, and difficulty breathing, particularly during exertion. Diagnosis is typically made through echocardiography, which reveals the structural anomalies of the heart. Management often involves surgical intervention to repair the septal defects and reconstruct the atrioventricular valve, aiming to restore normal hemodynamics and improve the patient's quality of life. Long-term follow-up is essential to monitor for potential complications, including arrhythmias and valve dysfunction.

Code Complexity Analysis

Complexity Rating: Medium

Medium Complexity

Complexity Factors

  • Variability in clinical presentation and severity of symptoms
  • Need for detailed anatomical descriptions in documentation
  • Potential for associated congenital anomalies
  • Variations in surgical repair techniques

Audit Risk Factors

  • Inadequate documentation of the defect's specifics
  • Failure to capture associated congenital anomalies
  • Incorrect coding of surgical procedures performed
  • Lack of follow-up documentation for long-term care

Specialty Focus

Medical Specialties

Pediatrics

Documentation Requirements

Pediatric documentation should include growth parameters, developmental milestones, and specific symptoms related to heart function.

Common Clinical Scenarios

Common scenarios include routine check-ups for children with known congenital heart defects, pre-operative assessments, and post-operative follow-ups.

Billing Considerations

Consideration must be given to the child's age, growth patterns, and any developmental delays that may arise from the condition.

Genetics

Documentation Requirements

Genetic documentation should include family history of congenital heart defects and any chromosomal abnormalities identified through testing.

Common Clinical Scenarios

Scenarios may involve genetic counseling for families with a history of congenital heart defects or syndromic presentations.

Billing Considerations

Genetic testing results should be clearly documented to support any associated syndromes or chromosomal abnormalities.

Coding Guidelines

Inclusion Criteria

Use Q21.21 When
  • According to ICD
  • CM guidelines, congenital conditions should be coded based on the specific anatomical and physiological characteristics of the defect
  • Documentation must support the diagnosis and any associated conditions

Exclusion Criteria

Do NOT use Q21.21 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 partial AVSD.

Documentation Requirements

Operative report detailing the procedure and findings.

Specialty Considerations

Pediatric cardiology and cardiothoracic surgery documentation must be precise.

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 the accuracy of data collection and reimbursement processes. This specificity aids in better tracking of congenital conditions and their outcomes.

ICD-9 vs ICD-10

The transition to ICD-10 has allowed for more specific coding of congenital heart defects, improving the accuracy of data collection and reimbursement processes. This specificity aids in better tracking of congenital conditions and their outcomes.

Reimbursement & Billing Impact

reimbursement processes. This specificity aids in better tracking of congenital conditions and their outcomes.

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 partial and complete atrioventricular septal defect?

Partial AVSD involves a single atrioventricular valve and is associated with an ASD and VSD, while complete AVSD has a more complex structure with two atrioventricular valves and is often associated with additional anomalies.