The Qualifier None is identified by letter "Z" and occupies the 6th position in the ICD10-PCS procedure code structure.
Below a selection of ICD 10 PCS codes related to C715YZ
Planar Nucl Med Imag Head & Neck Lymph w Oth Radionuclide
Planar Nucl Med Imag Head & Neck Lymph w Technetium 99m