Goodness, you are right, it can only be used as secondary code. Our home health nurse wanted to use V67.2, but we saw that was only for use if treatment was completed, which it is not (it also looks like a code for treating physician only as well?). She is basically assessing the effects of chemotherapy as part of her nursing assignment, but not, as V58.83 says, measuring drug levels in the body. I am new at this, and we have a very small home health side, really for pre-hospice pts. We were advised by another home health agency to use V58.11, but we are not providing the chemotherapy either, so that can't be right.