ICD 10 Coding Alert

Question: I’m new to coding and have noticed that both brackets and parentheses are used in my ICD-10-CM code book. Do they signify different meanings?

Nebraska Subscriber

Answer: Brackets and parentheses serve different purposes in ICD-10-CM. In the Alphabetic Index, brackets identify a manifestation code that you should report with the code for the underlying condition. The code in brackets identifies a manifestation code; coders should verify any applicable etiology/manifestation conventions, including Code first and Use additional code instructions, in the Tabular List. In the Tabular List, brackets enclose synonyms, alternative wording, and explanatory phrases.

For example, an Alphabetic Index entry may direct the coder to an underlying disease code followed by a manifestation code shown in brackets. That bracketed code signals the manifestation relationship, but the coder should still verify both codes and any sequencing instructions in the Tabular List.

Parentheses, on the other hand, enclose supplementary words called nonessential modifiers. A nonessential modifier may appear (or be absent) in the documentation without changing the code assigned to the main term. For instance, if the Index lists a condition followed by a descriptor in parentheses, the same code may apply regardless of whether the provider documents that parenthetical descriptor — if other documentation does not direct to a different entry.

Treat brackets as a signal of a manifestation code in the Alphabetic Index and as explanatory language, synonyms, or alternative wording in the Tabular List. Treat parentheses as containing optional wording that does not affect code selection. In every case, verify the final code assignment in the Tabular List and follow all applicable instructional notes.

Rachel Dorrell, MA, MS, CPC-A, CPPM, Production Editor, AAPC