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Healthcare Classifications and Terminologies

What is the ICD-10-CM?

ICD-10-CM is a classification system which is used for coding diagnoses associated with healthcare utilization within the United States.

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