ICD-10-CM 2027
ICD-10 code for vein anomaly
From the official ICD-10-CM alphabetic index entry “Anomaly, anomalous (congenital) (unspecified type) › vein (s) (peripheral)”. Page updated September 29, 2026.
About coding vein anomaly
The ICD-10-CM code for vein anomaly is Q27.9 (Congenital malformation of peripheral vascular system, 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 Q27.9.
Within Q27, choose Q27.9 (Congenital malformation of peripheral vascular system, unspecified) only when documentation doesn't support a more specific option: congenital absence and hypoplasia of umbilical artery (Q27.0), congenital renal artery stenosis (Q27.1), other congenital malformations of renal artery (Q27.2), arteriovenous malformation (peripheral) (Q27.3), congenital phlebectasia (Q27.4) and other specified congenital malformations of peripheral vascular system (Q27.8).
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 299 (Peripheral Vascular Disorders with MCC, relative weight 1.5842), DRG 300 (Peripheral Vascular Disorders with CC, relative weight 1.0464) and DRG 301 (Peripheral Vascular Disorders without CC/MCC, relative weight 0.7133), 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 vein anomaly codes (official index)
- brain Q28.3 — Other malformations of cerebral vessels
- cerebral Q28.3 — Other malformations of cerebral vessels
- coronary Q24.5 — Malformation of coronary vessels
- developmental Q28.3 — Other malformations of cerebral vessels
- great Q26.9 — Congenital malformation of great vein, unspecified
- specified NEC Q26.8 — Other congenital malformations of great veins
Common questions about vein anomaly ICD-10 codes
What is the ICD-10 code for vein anomaly?
- Q27.9 — Congenital malformation of peripheral vascular system, unspecified. More specific codes apply when the documentation supports them: Q28.3, Q28.3, Q24.5, Q28.3 and others below.
What is the ICD-10 code for brain vein anomaly?
- Q28.3 — Other malformations of cerebral vessels.
What is the ICD-10 code for cerebral vein anomaly?
- Q28.3 — Other malformations of cerebral vessels.
What is the ICD-10 code for coronary vein anomaly?
- Q24.5 — Malformation of coronary vessels.
What is the ICD-10 code for developmental vein anomaly?
- Q28.3 — Other malformations of cerebral vessels.
What is the ICD-10 code for great vein anomaly?
- Q26.9 — Congenital malformation of great vein, unspecified.
Is Q27.9 billable?
- Yes. Q27.9 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Q27.9 be used as a principal diagnosis?
- Yes. The Medicare Code Editor doesn't restrict Q27.9 as a principal diagnosis.
Is Q27.9 a CC or MCC?
- No. Q27.9 is neither a CC nor an MCC under MS-DRG v44.0.