I82.B12

HCC Category Mapping

What This Code Means

A sudden blood clot that has formed in the left subclavian vein (a major vein near the collarbone), potentially causing acute obstruction.

Coding Tips

• •Confirm documentation explicitly states 'acute' and 'left' to ensure accurate laterality and acuity coding
• •Distinguish from chronic subclavian vein thrombosis which uses different code series

Clinical Significance

Acute subclavian vein thrombosis represents a significant vascular event that can lead to pulmonary embolism, post-thrombotic syndrome, and recurrent venous thromboembolism. This diagnosis is critical for risk adjustment as it reflects active vascular disease requiring anticoagulation therapy, monitoring, and potentially invasive interventions. Accurate capture ensures appropriate resource allocation for ongoing management and complication prevention.

Documentation Requirements

• ✓Provider documentation explicitly stating acute embolism or thrombosis of the subclavian vein
• ✓Laterality must be documented (left side) — 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
• ✓Date of onset or timeframe establishing the acute nature of the condition
• ✓Any precipitating factors (central line placement, surgery, malignancy, hypercoagulable state)

Commonly Confused Codes