2018 ICD-10 PCS (Procedure Coding System) complete online reference.
ICD-10-PCS (Procedure Codes) has been developed as a replacement for Volume 3 of the ICD-9-CM. ICD-10-PCS has a 7 character alpha-numeric code structure that provides a unique code for all substantially different procedures, and allows new procedures to be incorporated as new codes. All procedures currently performed can be specified in ICD-10-PCS.
The first character always specifies the section. The 2nd - 7th characters mean the same thing within each section, but may mean different things in other sections. In all sections, the third character specifies the general type of procedure performed, while the other characters give additional information.
The 1st character of the code identifies the section. Sections relate to the type of procedure. For example, a chest x-ray is an imaging procedure and a breast biopsy is a medical and surgical procedure.