ICD-10-CM > I00-I99 > I80-I89 > I87 > I87.0 > I87.01 I87.01 Postthrombotic syndrome with ulcer Non-Billable/Non-Specific Use Additional code to specify site and severity of ulcer (L97.-) Codes I87.011Postthrombotic syndrome with ulcer of right lower extremityI87.012Postthrombotic syndrome with ulcer of left lower extremityI87.013Postthrombotic syndrome with ulcer of bilateral lower extremityI87.019Postthrombotic syndrome with ulcer of unspecified lower extremity