FY2027 ICD-10-CM reference
Q21: Congenital malformations of cardiac septa
By the HCC Buddy Coding Team
The official ICD-10-CM descriptor is Congenital malformations of cardiac septa. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Nonbillable heading. Verified against the official FY2027 order file.
More specific FY2027 codes
- Q21.0: Ventricular septal defectBillable code
- Q21.1: Atrial septal defectNonbillable heading
- Q21.2: Atrioventricular septal defectNonbillable heading
- Q21.3: Tetralogy of FallotBillable code
- Q21.4: Aortopulmonary septal defectBillable code
- Q21.8: Other congenital malformations of cardiac septaBillable code
- Q21.9: Congenital malformation of cardiac septum, unspecifiedBillable code
FY2027 Tabular instructions
Instructions below include applicable chapter, section and parent-code notes. Each note identifies where it appears in the official source.
Instructional note
Codes from this chapter are not for use on maternal records
Source: Q00-QA1 (chapter, inherited).
Excludes2
inborn errors of metabolism (E70-E88)
Source: Q00-QA1 (chapter, inherited).
Excludes1
acquired cardiac septal defect (I51.0)
Source: Q21 (category, direct).
Compare the FY2027 additions, removals and billable-status changes
What does Q21 mean in FY2027?
The official ICD-10-CM descriptor is Congenital malformations of cardiac septa. The FY2027 annual edition starts October 1, 2026. Check the edition that applies to the encounter or inpatient discharge, including any April update.
Is Q21 billable in FY2027?
The FY2027 order file marks Q21 as a nonbillable heading. Select a complete billable child code.
Does Q21 map to an HCC?
Risk-model mapping is not applicable to this nonbillable heading. Check a complete billable child code.
Source: CMS FY2027 ICD-10-CM order file. Read the FY2027 Official Guidelines.
Review the FY2026 April edition