ICD-10 Q21.1
Non-Billable HeaderAtrial septal defect
About ICD-10-CM Q21.1
ICD-10-CM code Q21.1 represents Atrial septal defect. This is a non-billable header code in the Congenital Malformations chapter (block Q21). The 2026 edition of ICD-10-CM Q21.1 became effective on October 1, 2025. Non-billable codes cannot be used as a primary or secondary diagnosis on a claim, use a more specific child code instead.
Type 2 Excludes
Not included here, the excluded code is not part of Q21.1, but a patient may have both conditions at the same time. Both codes may be coded together when applicable.
- ostium primum atrial septal defect (type I) (Q21.20)
Medicare LCD Coverage for Q21.1
Local Coverage Determinations (LCDs) from CMS MACs that list Q21.1 as a covered diagnosis.
This doesn't mean the code isn't covered, it means no MAC has issued a Local Coverage Determination naming this specific code. Coverage may still apply under National Coverage Determinations or general medical-necessity rules.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing Q21.1.
Our payer policy database covers Aetna, Cigna, Anthem, BCBS, Humana, and Medicare Advantage plans, but Q21.1 doesn't currently appear in any indexed policy. The code may still be covered under standard plan benefits.
CPT Codes Commonly Billed with Q21.1
Procedures frequently paired with this diagnosis based on PayerReady's Dx↔Px linkage data.
- 93306 Echo with Doppler — heart failure, cardiomyopathy, mitral/aortic/tricuspid valve disease, chest pain, dyspnea, CAD, pulmonary HTN, ASD, VSD, congenital valve Cardiology
Convert Q21.1 to ICD-9-CM
Per CMS General Equivalence Mappings (GEMs), useful for legacy data review and historical claim analysis.
| ICD-10 | ICD-9 | Mapping Flags |
|---|---|---|
| Q21.1 | 7455 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To Q21.1
Other codes in section Q20-Q28 (Congenital malformations of the circulatory system).
ICD-10 Q21.1, Billing FAQ
Is ICD-10 code Q21.1 billable? +
No, Q21.1 is a non-billable header code. Use a more specific child code from block Q21 when submitting claims.
What codes are Type 2 Excludes for Q21.1? +
Type 2 Excludes (may be coded together when both conditions exist): ostium primum atrial septal defect (type I) (Q21.20)
What CPT codes are commonly billed with Q21.1? +
Procedures frequently paired with Q21.1 include: 93306.
What ICD-9 codes does Q21.1 map to? +
Per CMS GEMs, Q21.1 maps to ICD-9 codes: 7455. Useful for legacy data review and historical claim analysis.
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Reviewed by the PayerReady Medical Coding Team
Verified against the CMS 2026 code set on June 1, 2026.
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