ICD-10 Code I87.021 – Postthrombotic syndrome with inflammation of right lower extremity (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I87.021 – Postthrombotic syndrome with inflammation of right lower extremity
What it is
I87.021 identifies postthrombotic syndrome affecting the right lower extremity with inflammation. It describes chronic venous damage after a prior deep vein thrombosis, with persistent inflammatory changes in the right leg.
Clinical signs
Look for chronic leg swelling, pain, heaviness, skin discoloration, and signs of venous inflammation in the right lower extremity. Clinical features vary; refer to documentation.
When to use this code
Use this code when the provider documents postthrombotic syndrome in the right leg and specifically notes inflammation. It is appropriate for sequelae of prior thrombosis, not for an acute clot. Check documentation if laterality or inflammatory involvement is unclear.
Do not use for
Do not use it for acute deep vein thrombosis, nonspecific leg edema, or postthrombotic syndrome without right-sided involvement. If inflammation is not documented, check documentation.
Coding tip
Assign I87.021 only when both postthrombotic syndrome and right-leg inflammation are clearly stated in the record.