How are you billing for pre and post hydration done on days separate from chemotherapy. So a patient is scheduled for chemotherapy on Tuesday, but comes in on Monday for pre-hydration, gets additional hydration and chemo on Tuesday, and more post-hydration on Wednesday. When we bill for hydration on the same day as chemo, we are just using the Z51.11 and cancer diagnosis, but are not sure if we can extend this to a day where chemotherapy is not being given. The patient does not have active dehydration, nausea or vomiting. This is all preventative. Any thoughts would be appreciated.