ICD-10-CM Q21.1 is the diagnosis code for Atrial septal defect. This code falls under the section "Congenital malformations of the circulatory system" within Chapter 17 â Congenital malformations, deformations and chromosomal abnormalities (Q00-QA0). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
The following conditions are not included in Q21.1. If the patient has both, code each condition separately:
Understanding where Q21.1 sits in the ICD-10-CM classification helps ensure proper coding:
No, Q21.1 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
Q21.1 is the ICD-10-CM diagnosis code for "Atrial septal defect". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
The parent code of Q21.1 is Q21 ("Congenital malformations of cardiac septa"). Q21.1 provides a more specific classification within this category.
Q21.1 is located in Section Q20-Q28 â "Congenital malformations of the circulatory system" within Chapter 17 of the ICD-10-CM Tabular List.
Q21.1 has 8 sub-code(s) that provide more specific detail: Q21.10, Q21.11, Q21.12, Q21.13, Q21.14 and more.
Use Q21.1 when the patients documented diagnosis matches "Atrial septal defect" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Atrial septal defect is Q21.1.
No, Q21.1 is non-billable. Use a more specific sub-code for primary diagnosis billing.
Q21.1 is in Chapter 17 of the ICD-10-CM Tabular List.
Yes, Q21.1 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.