Wiki Infusion Orders

[jesse_lost05]

I am fairly new to coding and have been coding infusions recently. I have been coming across orders for medication/administration of medication that are missing the diagnosis codes. I had always thought if you were missing the diagnosis code you would either need a new order or the physician could write in a diagnosis code but he would have to sign,date,time, and initial the correction. Is this correct? When I send these orders back the infusion clinic seems to be writing in the codes without kicking it back to the ordering provider.