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 0JN4X
Release Rt Neck Subcu/Fascia, Open Approach
Release Rt Neck Subcu/Fascia, Perc Approach
Release Rt Neck Subcu/Fascia, Extern Approach