36415 & office visits

Been reading the responses to a question on the use of this code and one person said this isn't to be used for diagnostic or therapeutic purposes (routine venipncture) and is to be billed on UB for facility side. Another said to use mod 25 on office visit and attach 36415 to it's own dx. Our providers have begun to code it with a huge portion of our office visits. We are a hospital owned Rural Health clinic. They seem to be using it for routine venipuncture and don't always have seperate dx. Do I bill for it along with the E&M or is it bundled with that? Or do I use a mod 25 on the E&M each time a 36415 is ordered; or is there a diferent CPT® for routine venipunctures done in an office setting and billing provider charges? Having trouble wrapping my head around this.

Sandy