This 3-hour class will address coding dilemmas identified through quality control of registry data and present solutions with rationale for determining the number of primary tumors using the Solid Tumor Rules; assigning ICD-O-3 topography and histology codes using the ICD-O-3 Manual and Solid Tumor Rules; completing the stage of disease data items using AJCC Cancer Staging Manual, 8th Edition and Summary Stage 2020; and completing treatment data items as required by all standard setters.