Can a drug test for Parole distinguish between Hydrocodone and Oxycodone?

I wouldn't worry so much as to whether or not the test can distinguish the two. Rather, I would concern myself with the fact that drug use may be considered a violation of parole and that I better have medical documentation for anything that may show up on the test. Just to add to what was said and to give you a answer since the answer given above was really not a answer but advise. To answer your question, Normally the test is a broad analisys of drugs. They will normally test for Opiates in general and then if you have a positive reading for Opiates in general they will go back and conduct a specialized test to see what type of Opiate it is. So yes they can determine exactly what type of Opiate you took. Hydro or Oxy or any other and they can also determine the amount that you took. But the first test is normally just a broad screen for Opiates in general.