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ICD-10, ICD-10-CM, & ICD-10-PCS

ICD-10-CM and ICD-10-PCS are classification systems used for coding diagnoses, procedures, and services provided by the U.S. health care system.

Obtaining ICD-10-CM Codes

The most direct source of the ICD-10-CM code set is the National Center for Health Statistics (NCHS).  NCHS is responsible for maintaining the ICD-10-CM code set.  There is no cost to download ICD-10-CM from the NCHS website.

ICD-10-CM primarily consists of the ICD-10-CM Official Guidelines for Coding and Reporting, Index, and the Tabular List. The index is comprised of the following: Index to Diseases and Injuries, Table of Neoplasms, Table of Drugs and Chemicals, and External Cause of Injuries Index.

The code set is also commercially published in both print and electronic format by a number of publishers and vendors.

Basic ICD-10-CM Coding Steps

A crucial component of the ICD-10-CM code set is the document, ICD-10-CM Official Guidelines for Coding and Reporting. Before working with ICD-10-CM, the user of ICD-10-CM should become familiar with all of these guidelines. In particular, subsections I.A and I.B of the official coding guidelines describe basic coding rules and conventions. Guideline I.B.1 explains the process for locating a code in ICD-10-CM. As noted in this guideline it is essential to use both the index and tabular list when coding in ICD-10-CM. This is essential regardless of the level of clinical knowledge and expertise by the person using the code book so that coded data are consistently and reliably created.

Figure 1 outlines the basic ICD-10-CM coding steps. Refer to the official coding guidelines for additional information on steps 1, 2, and 3. In addition to the ICD-10-CM Official Guidelines for Coding and Reporting, coding professionals should also be familiar with applicable coding advice found in American Hospital Association’s Coding Clinic for ICD-10-CM and ICD-10-PCS as well as relevant payer-specific coding guidelines and facility-specific coding guidelines.

Coding Resources

Coding Clinic for ICD-10-CM and ICD-10-PCS

American Hospital Association publishes Coding Clinic for ICD-10-CM and ICD-10-PCS. It contains coding advice as designated by the four Cooperating Parties (American Hospital Association, American Health Information Management Association, Centers for Medicare and Medicaid Services, and National Center for Health Statistics) and the Editorial Advisory Board. This quarterly newsletter is available for purchase at