How do you use square brackets in medical billing and coding?

In medical billing and coding, square brackets are used to enclose synonyms, alternative terminology, or explanatory phrases within the International Classification of Diseases (ICD) coding system. They help clarify the meaning of a code or provide additional context for specific diagnoses. For example, a code may include a term in brackets that indicates a related condition or a variation of the main diagnosis. This use ensures accurate coding and helps prevent misunderstandings in billing and documentation.