I am new to Oncology and we are having a disagreement with the ICD-9 coding of infusion visits when the patient is only in the office for an infusion visit (and not seeing the MD on the same day). One person says that V58.11 needs to be the primary diagnosis of the infusion visit and that we can use the neoplasm as the secondary code, where another person is saying that V58.11 is for an encounter and does not feel that infusion visits are encounters. She feels the primary diagnosis should be the neoplasm. Can someone please help me to understand which is correct.