ICD-10-PCS-Historical Perspective:

The International Classification of Diseases, Tenth Revision, Procedure Coding System (ICD-10-PCS) was developed as a replacement for the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) volume 3, Procedures.This version of ICD, is in use since January 1979.

ICD-9-CM Volume 3 codes are maximum 4 digit alphanumeric codes with a decimal point after first two digits.

After some year of its usage it soon became apparent that with the limitation of a four-digit system, there was little room for further expansion.

In 1992, HCFA realized a more comprehensive and organized approach was needed towards classifying the procedure coding system and funded a project with 3M Health Information Systems to produce a preliminary design for a replacement of ICD. After studying the problem, 3M concluded that a completely new system would be the best solution.

The new procedure coding system was titled International Classification of Diseases, Tenth Revision, Procedure Coding System (ICD-10-PCS), to replace ICD-9-CM Volume 3. CMS (the then HCFA) awarded the contract to 3M in 1995.

The objectives of the project were to develop a new procedure coding classification for improving accuracy and enhance efficiency in procedure coding and bring maximum specificity in defining the codes, which improves communication in healthcare transactions.

With the following essential characteristics and general guidelines the development ICD-10-PCS was achieved.

Essential characteristics:
  • completeness
  • a unique code for all substantially different procedures
  • future expandability
  • a system structure that allows incorporation of new procedures as unique codes
  • standard terminology—the coding system includes definitions of the terminology used. While the meaning of the specific words can vary in common usage, the coding scheme does not include multiple meanings for the same term. Each term is assigned a specific meaning
  • multiaxial—the system has a multiaxial structure with each code character possessing the same meaning within the specific procedure section and across procedure sections also to the extent possible

General guidelines:
  • not including diagnostic information in the procedure descriptioneg. hernia repair (hernia is a diagnostic term)
  • limiting the not otherwise specified (NOS) option
  • not allowing a not elsewhere classified option (NEC), except for new devices
  • defining all possible procedures

Basics of ICD-10-PCS
  • All codes must have 7 characters without and decimal point with each character describing different aspects of a procedure. Below is a sample of a code structure with different character positions described from Medical and Surgical section of ICD-10-PCS.

  • 1 2 3 4 5 6 7


    Body System

    Root Operation

    Body Part




  • All procedures currently performed can be specified in ICD-10-PCS.
  • ICD-10-PCS has a seven character alphanumeric code structure. Each character contains up to 34 possible values.
  • The ten digits 0-9 and the 24 letters A-H,J-N and P-Z may be used in each character. The letters O and I are not used in order to avoid confusion with the digits 0 and 1.
  • Procedures are divided into 16 sections that identify the general type of procedure (e.g., medical and surgical, obstetrics, imaging).The first character of the procedure code always specifies the section.
  • The second through seventh characters mean the same thing within each section, but may mean different in other sections. (eg. second character "0" in medical and surgical section means central nervous system in the entire section but means pregnancy in obstetric section)
  • In all sections, the third character specifies the general type of procedure performed (e.g., resection, transfusion, fluoroscopy), while the other characters give additional information such as the body part and approach, device type. In most of the sections of ICD-10-PCS the third character is referred asroot operation.
  • Most of the procedures in different sections of ICD-10-PCS are identified by root operations. The root operation identifies the objective of the procedure. In the above table "removal" is the root operation that describes the objective of the procedure.
  • Each root operation has a precise definition. For example, the root operation insertion is used for procedures where devices are put in or on a body part. If a device is taken out but no equivalent device is put in, then the root operation removal is used.
  • The body part is specified in the fourth character. The body part indicates the specific part of the body system on which the procedure was performed (e.g., duodenum).
  • The technique used to reach the site of the procedure is specified in the fifth character. It is referred as approachin most of the ICD-10-PCS codes. There are 7 different approaches has been defined in ICD-10-PCS.
  • The sixth and seventh character in a table adds some additional attributes to the procedure code to describe it further specifically in different sections of ICD-10-PCS in different meaning.
  • The ICD-10-PCS is made up of three separate parts i.e., Tables, Index and List of Codes.
  • The Index allows us to locate the codes to by an alphabetic lookup. The index entry refers to a specific location in the Tables.
  • The Tables must be used in order to construct a complete and valid code. There are no completely built in codes in ICD-10-PCS. List of codes can be prepared using the tables.
  • Tableconsist rows that specify the valid combination of code values after the first three characters. In most sections of the system, each table contains a description of first three characters i.e., for the name of the section, the body system, and the root operation at the top of the table (eg. 01P in the table below). The rows in the table are filled with character values for each character of the 7 character code of ICD-10-PCS with their description for character four through seven separated by vertical rows in between them. A code may be constructed by adding required 4th, 5th, 6th and 7th character to the first three characters of the table as per the documentation details. While constructing a code from the table, the 4th to 7th characters are selected strictly from the same row in a table. Example in the following table 01P code 01PYX0Z using the 2nd row for 4th to 7th character is a valid code. Whereas a code with combination of characters from both row of table such as 01PYX7Z is a wrong code.

0 Medical and Surgical

1 Peripheral Nervous System

P Removal: Taking out off a device from a body part

Body Part Character 4 Approach Character 5 Device character 6 Qualifier Character 7
Y Peripheral Nerve 0 Open
3 Percutaneous
4 Percutaneous Endoscopic
0 Drainage Device
2 Monitoring Device
7 Autologous Tissue Substitute
M Electrode
Z No Qualifier
Y Peripheral Nerve X External 0 Drainage Device
2 Monitoring Device
M Electrode
Z No Qualifier