The ICD-10-CM index and its tabular list must both be used during code assignment because the ICD-10-CM index _____.

The ICD-10-CM index must be used alongside the tabular list during code assignment because it does not always provide the complete ICD-10-CM code. The index serves as a valuable tool for finding potential codes based on the terms provided by the healthcare provider. However, it typically offers the preliminary steps to locate a code rather than the complete coding information.

To finalize code assignment, it's essential to cross-reference with the tabular list, which presents a complete and detailed arrangement of all codes, including necessary additional characters, that fulfill coding requirements. The tabular list not only confirms the codes found in the index but also provides descriptions, guidelines, and sometimes additional coding instructions. Therefore, relying solely on the index could lead to incomplete or inaccurate codes, emphasizing the importance of utilizing both resources to ensure accurate medical coding.