ICD-10-CM 2027
ICD-10 code for heart accessory
From the official ICD-10-CM alphabetic index entry “Accessory (congenital) › heart”. Page updated September 29, 2026.
About coding heart accessory
The ICD-10-CM code for heart accessory is Q24.8 (Other specified congenital malformations of heart). The official index lists 2 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on Q24.8.
Within Q24, choose Q24.8 (Other specified congenital malformations of heart) 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 congenital malformation of heart, unspecified (Q24.9).
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 heart accessory codes (official index)
Common questions about heart accessory ICD-10 codes
What is the ICD-10 code for heart accessory?
- Q24.8 — Other specified congenital malformations of heart. More specific codes apply when the documentation supports them: Q24.8, Q22.3.
What is the ICD-10 code for valve nec heart accessory?
- Q24.8 — Other specified congenital malformations of heart.
Is Q24.8 billable?
- Yes. Q24.8 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Q24.8 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict Q24.8 as a principal diagnosis.
Is Q24.8 a CC or MCC?
- No. Q24.8 is neither a CC nor an MCC under MS-DRG v44.0.