Q21.21
Billable

Partial atrioventricular septal defect

Billable / Specific Code

What is Partial atrioventricular septal defect?

ICD-10-CM Q21.21 is the diagnosis code for Partial atrioventricular septal defect. This code falls under the section "Congenital malformations of the circulatory system" within Chapter 17 — Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0). It is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.

💡 Inclusions

Coding Guidelines for Q21.21

✅ This Code Includes

  • Incomplete atrioventricular canal
  • Incomplete atrioventricular septal defect
  • Incomplete endocardial cushion defect
  • Ostium primum atrial septal defect (type I) with separate atrioventricular valves
  • Partial atrioventricular canal
  • Partial endocardial cushion defect

ICD-10-CM Code Hierarchy

Understanding where Q21.21 sits in the ICD-10-CM classification helps ensure proper coding:

Related Codes

Frequently Asked Questions

Is Q21.21 a billable ICD-10-CM code?

Yes, Q21.21 is a billable/specific ICD-10-CM code that can be used to indicate a diagnosis for reimbursement purposes.

What does Q21.21 mean?

Q21.21 is the ICD-10-CM diagnosis code for "Partial atrioventricular septal defect". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.

What is the parent code of Q21.21?

The parent code of Q21.21 is Q21.2 ("Atrioventricular septal defect"). Q21.21 provides a more specific classification within this category.

What section is Q21.21 in?

Q21.21 is located in Section Q20-Q28 — "Congenital malformations of the circulatory system" within Chapter 17 of the ICD-10-CM Tabular List.

When should I use Q21.21?

Use Q21.21 when the patients documented diagnosis matches "Partial atrioventricular septal defect" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.

People Also Ask

What is the ICD-10 code for Partial atrioventricular septal defect?

The ICD-10-CM code for Partial atrioventricular septal defect is Q21.21.

Can Q21.21 be used for primary diagnosis?

Yes, Q21.21 can be used as a primary diagnosis code since it is billable and specific.

What chapter is Q21.21 in?

Q21.21 is in Chapter 17 of the ICD-10-CM Tabular List.

Is Q21.21 valid for 2026?

Yes, Q21.21 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.

See Also

← PreviousQ21.20Atrioventricular septal defect, unspecified as to partial or completeNext →Q21.22Transitional atrioventricular septal defect
Code Details
Q21.21
Partial atrioventricular septal defect
Billable / Specific Code
17 — Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0)
Q20-Q28 — Congenital malformations of the circulatory system
2026 ICD-10-CM