ICD-10 Q21.0
Billable / Specific CCVentricular septal defect
About ICD-10-CM Q21.0
ICD-10-CM code Q21.0 represents Ventricular septal defect. This is a billable/specific code in the Congenital Malformations chapter (block Q21). The 2026 edition of ICD-10-CM Q21.0 became effective on October 1, 2025.
Coding Tips for Q21.0
Specialist guidance from the PayerReady Medical Coding Team. Specificity warnings, HCC capture rules, sequencing notes.
Q21.0 is designated CC for MS-DRG grouping. On inpatient claims, this code can shift the DRG to the with-CC variant when documented as a present-on-admission secondary diagnosis. Hospital CDI programs flag CC opportunities during chart review. Failure to capture this code may leave 30 to 80 percent of the inpatient stay revenue unrealized.
Inclusion Terms / Approximate Synonyms
Clinical terms and conditions classified under Q21.0. Per CMS ICD-10-CM Tabular 2026.
- Roger's disease
Inpatient DRG Impact, CC
codes Ventricular septal defect. As a Complication/Comorbidity (CC), this contributes to DRG severity adjustment when documented alongside the principal diagnosis.
Medicare LCD Coverage for Q21.0
Local Coverage Determinations (LCDs) from CMS MACs that list Q21.0 as a covered diagnosis.
Showing top 10 of 349 total . Click a CPT for full coverage scope.
Commercial Payer Coverage
Coverage policies from major commercial payers referencing Q21.0.
3 Cigna
5 Medicare
CPT Codes Commonly Billed with Q21.0
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 Q21.0 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 |
|---|---|---|
| Q21.0 | 7454 | 00000 |
Flags format (5 digits): Approximate · No Map · Combination · Scenario · Choice List. Source: CMS 2017 GEMs (final version).
Codes Adjacent To Q21.0
Other codes in section Q20-Q28 (Congenital malformations of the circulatory system).
ICD-10 Q21.0, Billing FAQ
Is ICD-10 code Q21.0 billable? +
Yes, Q21.0 is a billable ICD-10-CM code that can appear as a primary or secondary diagnosis on claims.
What other names or terms map to Q21.0? +
ICD-10 Q21.0 includes: Roger's disease.
Is Q21.0 a CC or MCC for inpatient DRG? +
Yes, this code is designated as CC. Documenting as a secondary diagnosis on inpatient claims can shift the DRG to a higher-weighted category.
What CPT codes are commonly billed with Q21.0? +
Procedures frequently paired with Q21.0 include: 93306.
What ICD-9 codes does Q21.0 map to? +
Per CMS GEMs, Q21.0 maps to ICD-9 codes: 7454. 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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