What do parentheses signify in ICD-10-CM coding?

In ICD-10-CM coding, parentheses are used to indicate nonessential modifiers. These modifiers provide additional information about the condition but do not affect the code itself. This means that the information contained within the parentheses is supplementary and may help clarify certain aspects of the diagnosis without altering the classification of the disease or condition. For instance, if a diagnosis code has a term in parentheses, it suggests that the term can be present or absent, and the base code still applies regardless of whether the modifier is included. This allows healthcare coders to capture more specific details while maintaining the integrity of the primary diagnosis code.

In contrast, the other options refer to aspects of coding that do not accurately describe the function of parentheses in ICD-10-CM. Some codes may indicate mandatory instructions or additional required codes, but parentheses specifically signify nonessential information that should not be mistaken for items that are mandatory or conditions that cannot coexist.