Punctuation

[ ] Brackets are used in the Tabular List to enclose synonyms, alternative wording or explanatory phrases. Brackets are used in the Alphabetic Index to identify manifestation codes. ( ) Parentheses are used in both the Alphabetic Index and Tabular List to enclose supplementary words that may be present or absent in the statement of a disease or procedure without affecting the code number to which it is assigned.

The terms within the parentheses are referred to as nonessential modifiers. The nonessential modifiers in the Alphabetic Index to Diseases apply to subterms following a main term except when a nonessential modifier and a subentry are mutually exclusive, the subentry takes precedence.

For example, in the ICD-10-CM Alphabetic Index under the main term Enteritis, “acute” is a nonessential modifier and “chronic” is a subentry.

In this case, the nonessential modifier “acute” does not apply to the subentry “chronic”. : Colons are used in the Tabular List after an incomplete term which needs one or more of the modifiers following the colon to make it assignable to a given category. , Commas are used in the Alphabetic Index and have different meanings based on the context of the Index entry, including alternate verbiage, modifier (essential and nonessential), or alternative for “and/or.”