I82.B23

HCC Category Mapping

What This Code Means

Blood clots that have formed and persist in both the right and left subclavian veins (major veins near both collarbones).

Coding Tips

• •Use this code only when documentation clearly indicates chronic bilateral involvement of both subclavian veins
• •Do not use this code if only one side is affected; use the appropriate unilateral code instead

Clinical Significance

Chronic subclavian vein thrombosis indicates a long-standing vascular condition with persistent clot burden, reflecting ongoing risk for post-thrombotic syndrome, recurrent thromboembolism, and venous insufficiency. This diagnosis captures the sustained complexity of the patient's vascular disease and the need for long-term anticoagulation management, which is important for accurate risk adjustment.

Documentation Requirements

• ✓Provider documentation explicitly stating chronic embolism or thrombosis of the subclavian vein
• ✓Laterality must be documented (bilateral) — do not assume from context
• ✓Clinical findings supporting the diagnosis (e.g., swelling, pain, imaging results such as duplex ultrasound or CT venography)
• ✓Current treatment plan including anticoagulation therapy type, duration, and monitoring parameters
• ✓Duration or timeline establishing chronicity (e.g., 'long-standing,' 'diagnosed 6 months ago')
• ✓Evidence of ongoing monitoring or follow-up imaging confirming persistent thrombus

Commonly Confused Codes