Volume 3 of the International Classification of Diseases 9th Revision Clinical Modification (ICD-9-CM) has been used in the U.S. for the reporting of inpatient pro-cedures since 1979. The structure of Vol-ume 3 of ICD-9-CM has not allowed new procedures associated with rapidly chang-ing technology to be effectively incorpo-rated as new codes. As a result, in 1992 the U.S. Centers for Medicare and Medic-aid Services (CMS) funded a project to design a replacement for Volume 3 of ICD-9-CM. After a review of the preliminary design, CMS in 1995 awarded 3M Health Information Systems a three-year contract to complete development of the replace-ment system. The new system is the ICD-10 Procedure Coding System (ICD-10-PCS).
The development of ICD-10-PCS had as its goal the incorporation of four major attributes:
There should be a unique code for all substantially different procedures. In Volume 3 of ICD-9-CM, procedures on different body parts, with different approaches, or of different types are sometimes assigned to the same code.
As new procedures are developed, the structure of ICD-10-PCS should allow them to be easily incorporated as unique codes.
ICD-10-PCS codes should consist of independent characters, with each individual axis retaining its meaning across broad ranges of codes to the extent possible.
ICD-10-PCS should include definitions of the terminology used. While the meaning of specific words varies in common usage, ICD-10-PCS should not include multiple meanings for the same term, and each term must be assigned a specific meaning.
If these four objectives are met, then ICD-10-PCS should enhance the ability of health information coders to construct accurate codes with minimal effort. Withn the development of ICD-10-PCS, several general principles were followed:
When procedures are performed for specific diseases or disorders, the disease or disorder is not contained in the procedure code. There are no codes for procedures exclusive to aneurysms, cleft lip, strictures, neoplasms, hernias, etc. The diagnosis codes, not the procedure codes, specify the disease or disorder.
ICD-9-CM often provides a "not otherwise specified" code option. Certain NOS options made available in ICD-10-PCS are restricted to the uses laid out in the ICD-10-PCS draft guidelines. A minimal level of specificity is required for each component of the procedure.
ICD-9-CM often provides a "not elsewhere classified" code option, but because all significant components of a procedure are specified in ICD-10-PCS, there is generally no need for an NEC code option. However, limited NEC options are incorporated into ICD-10-PCS where necessary. For example, new devices are frequently developed, and therefore it is necessary to provide an "Other Device" option for use until the new device can be explicitly added to the coding system. Additional NEC options are discussed later, in the sections of the system where they occur.
All procedures currently performed can be specified in ICD-10-PCS. The frequency with which a procedure is performed was not a consideration in the development of the system. Rather, a unique code is available for variations of a procedure that can be performed.
ICD-10-PCS has a seven character alphanumeric code structure. Each character contains up to 34 possible values. Each value represents a specific option for the general character definition (e.g., stomach is one of the values for the body part character). 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.
The second through seventh characters mean the same thing within each section, but may mean different things in other sec-tions.
In all sections, the third character specifies the general type of procedure per-formed (e.g., resection, transfusion, fluoroscopy), while the other characters give additional information such as the body part and approach. In ICD-10-PCS, the term "procedure" refers to the complete specification of the seven characters.