The World Health Organization has maintained the International Classification of Diseases (ICD) for recording cause of death since 1893. It has updated the ICD periodically to reflect new discoveries in epidemiology and changes in medical understanding of disease.
The Centers for Medicare & Medicaid Services (CMS), the agency responsible for maintaining the inpatient procedure code set in the U.S., contracted with 3M Health Information Systems in 1993 to design and develop a procedural classification system that would replace Volume 3 of ICD-9-CM.
ICD-10-PCS was initially released in 1998. It has been updated annually since that time although it was not put into operation until 2015. The ICD-10-PCS code set has a logical, consistent structure that follows a logical consistent process down to the individual character level. Individual letters and numbers, called “values,” are selected in sequence to occupy the seven spaces of the code, called “characters.”. ICD-10-PCS is composed of 17 sections, represented by the numbers 0–9 and the letters B–D and F–H, and X. The broad procedure categories contained in these sections range from surgical procedures to substance abuse treatment and new technology. All codes in ICD-10-PCS are seven characters long. Each character in the seven-character code represents an aspect of the procedure, as shown in the following diagram:
For more information please refer to Billingncoding.com ICD 10 PCS sections
Resources:
https://www.cms.gov/Medicare/Coding/ICD10/Downloads/
https://www.who.int/classifications/icd