ICD-10-CM 2027
ICD-10 code for cardiac anomaly
From the official ICD-10-CM alphabetic index entry “Anomaly, anomalous (congenital) (unspecified type) › cardiac”. Page updated September 29, 2026.
About coding cardiac anomaly
The ICD-10-CM code for cardiac anomaly is Q24.9 (Congenital malformation of heart, unspecified). The official index lists 6 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on Q24.9.
Within Q24, choose Q24.9 (Congenital malformation of heart, unspecified) only when documentation doesn't support a more specific option: Dextrocardia (Q24.0), Levocardia (Q24.1), cor triatriatum (Q24.2), pulmonary infundibular stenosis (Q24.3), congenital subaortic stenosis (Q24.4), malformation of coronary vessels (Q24.5), congenital heart block (Q24.6) and other specified congenital malformations of heart (Q24.8).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 306 (Cardiac Congenital and Valvular Disorders with MCC, relative weight 1.546) and DRG 307 (Cardiac Congenital and Valvular Disorders without MCC, relative weight 0.9148), in MDC 05 (Diseases and Disorders of the Circulatory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific cardiac anomaly codes (official index)
- chambers Q20.9 — Congenital malformation of cardiac chambers and connections, unspecified
- specified NEC Q20.8 — Other congenital malformations of cardiac chambers and connections
- septal closure Q21.9 — Congenital malformation of cardiac septum, unspecified
- specified NEC Q21.8 — Other congenital malformations of cardiac septa
- valve NEC Q24.8 — Other specified congenital malformations of heart
- pulmonary Q22.3 — Other congenital malformations of pulmonary valve
Common questions about cardiac anomaly ICD-10 codes
What is the ICD-10 code for cardiac anomaly?
- Q24.9 — Congenital malformation of heart, unspecified. More specific codes apply when the documentation supports them: Q20.9, Q20.8, Q21.9, Q21.8 and others below.
What is the ICD-10 code for chambers cardiac anomaly?
- Q20.9 — Congenital malformation of cardiac chambers and connections, unspecified.
What is the ICD-10 code for septal closure cardiac anomaly?
- Q21.9 — Congenital malformation of cardiac septum, unspecified.
What is the ICD-10 code for valve nec cardiac anomaly?
- Q24.8 — Other specified congenital malformations of heart.
Is Q24.9 billable?
- Yes. Q24.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Q24.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict Q24.9 as a principal diagnosis.
Is Q24.9 a CC or MCC?
- No. Q24.9 is neither a CC nor an MCC under MS-DRG v44.0.