What are subterms in the ICD-10-CM index used for?

Subterms in the ICD-10-CM index serve a specific purpose in enhancing the accuracy and specificity of medical coding. They qualify a main term by providing additional details, such as alternative sites where a condition may occur, the etiology or cause of the condition, or the clinical status of the patient, such as whether the condition is acute or chronic. This added detail helps coders accurately represent the patient's diagnosis, ensuring proper coding for billing and statistical purposes.

Using subterms effectively allows for more precise coding, which is critical in the healthcare environment, as it directly impacts patient care, reimbursement, and data collection for health trends. By including these qualifiers, coders can select the most appropriate code that reflects the complexity and uniqueness of each patient's condition.