ICD-10 in Action: Chapter-specific guidelines

August 15, 2019

This Independence series, ICD-10 in Action, features articles to recap some of the ICD-10 diagnosis code changes, introduce new coding scenarios, and/or communicate updates to ICD-10 coding conventions.

The International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM) contains official guidelines for coding and reporting. There are coding conventions, general coding guidelines, and chapter-specific guidelines. These conventions and guidelines are rules and instructions that must be followed to classify and assign the most appropriate code. Understanding these guidelines and conventions are key to selecting the most appropriate code assignment.

  • Conventions. A set of rules for use of the classification independent of the guidelines. Coding conventions and instructions of the classification take precedence over guidelines. (e.g., Code First).
  • General guidelines. A set of rules and sequencing instructions for using the Tabular List and Alphabetic Index. These guidelines provide rules such as how to locate a code and obtain level of detail.
  • Chapter-specific guidelines. A set of rules for specific diagnoses and conditions in a particular classification.

It is necessary to review all three sections of the guidelines to fully understand the rules and instructions needed to code properly. Adherence to these guidelines is required under the Health Insurance Portability and Accountability Act (HIPAA). 

Chapter-specific guidelines

In addition to coding conventions and general coding guidelines, many of the chapters have a specific set of rules for diagnoses and conditions in a particular classification, known as chapter-specific guidelines. Unless otherwise noted, chapter-specific guidelines apply to all health care settings. These guidelines contain additional important information for reaching the most appropriate code assignment and proper sequencing of ICD-10-CM codes.

Chapter-specific guidelines containing sequencing information 

Examples from Chapter 21: Factors Influencing Health Status and Contact with Health Services (Z00-Z99)1 

3) Status

Z15 Genetic susceptibility to disease

Genetic susceptibility indicates that a person has a gene that increases the risk of that person developing the disease.

Codes from category Z15 should not be used as principal or first-listed codes. If the patient has the condition to which he/she is susceptible, and that condition is the reason for the encounter, the code for the current condition should be sequenced first. If the patient is being seen for follow-up after completed treatment for this condition, and the condition no longer exists, a follow-up code should be sequenced first, followed by the appropriate personal history and genetic susceptibility codes. If the purpose of the encounter is genetic counseling associated with procreative management, code Z31.5, Encounter for genetic counseling, should be assigned as the first-listed code, followed by a code from category Z15. Additional codes should be assigned for any applicable family or personal history.

16) Z Codes That May Only be Principal/First-Listed Diagnosis 

The following Z codes/categories may only be reported as the principal/first-listed diagnosis, except when there are multiple encounters on the same day and the medical records for the encounters are combined:

Z00          Encounter for general examination without complaint, suspected or reported diagnosis

Except: Z00.6

Z01          Encounter for other special examination without complaint, suspected or reported diagnosis

Additional resources

For more information, as well as full set of chapter-specific guidelines for ICD-10-CM, visit the Centers for Medicare & Medicaid Services website. 

We will continue to communicate ICD-10-specific information through this article series to review some of the ICD-10 diagnosis code changes. We encourage you to keep up with the latest news and information by visiting the ICD-10 section of our website.

1Centers for Medicare & Medicaid Services. “ICD-10-CM Official Guidelines for Coding and Reporting FY 2019.” 2019. Available from: www.cms.gov/Medicare/Coding/ICD10/Downloads/2019-ICD10-Coding-Guidelines-.pdf.