What is the purpose of using brackets in the Tabular List of ICD-10-CM coding?

The purpose of using brackets in the Tabular List of ICD-10-CM coding is to enclose supplementary words that provide additional information but are not essential for the code’s meaning. These supplementary terms may offer clarification or specifics regarding the condition being coded, but they do not change the fundamental meaning of the code itself. For example, a diagnosis of "diabetes mellitus" may include terms related to specific complications or type, which are placed within brackets to indicate that they are optional descriptors.

Understanding this function is crucial for accurate coding and ensures that coders are aware of the optional nature of these terms when determining the most appropriate code for a diagnosis.