The Approach External is identified by letter "X" and occupies the 5th position in the ICD10-PCS procedure code structure.
Below a selection of ICD 10 PCS codes related to 0H99X
Drainage of Perineum Skin, External Approach, Diagnostic
Drainage of Perineum Skin, External Approach
Drainage of Perineum Skin with Drain Dev, Extern Approach