Using the ICD-10-PCS Coding Manual: Index and Tables Instructions: Use the ICD-10-PCS index and tables to assign an appropriate code for each procedure. Remember! The ICD-10-PCS index entry usually contains just the first three or four characters of a code, which provides direction to the appropriate table to "build a code." When the entire seven-character code is provided in the index, verify its accuracy in the appropriate ICD-10-PCS table. Diagnostic open biopsy, left axillary lymph nodes