Hi Guest! It may have been a typo, but the CPT code should be 21249 instead of 20249 (20249 is not a valid CPT code). C76.0 stands for: Malignant neoplasm of head, face and neck C05.0 stands for: Malignant neoplasm of hard palate 21249 stands for: Reconstruction of mandible or maxilla, endosteal implant (eg, blade, cylinder); complete (4 or more) If the neoplasm was on the the hard palate only, you do not need C76.0. There are no standard modifiers to use on 21249. When you say you”re having trouble getting it on file/processed, what type of denial or rejection responses are you receiving? And just to be sure, are you billing for endosteal implants, or a palatal obturator?