If I am on state parole, can I use my medical marijuana?

It would not be safe to use medical marijuana while on parole. Parole and probation can include restrictions that prevent you from doing things that persons not on parole or probation could do: for example, you could be prohibited from associating with people with felong records, even though someone not on probation could do so. Similarly, if your parole includes a no-illegal-drugs restriction--and despite medical marijuana being legal with medical marijuana card, marijuana is otherwise still an illegal drug under state and federal law--using marijuana would be a breach of the terms of your parole. Your county's parole board could choose conclude that you violated your parole. While it's possible that were this to happen and you were to appeal this action that you might win in court, on the grounds that by holding you in violation of your parole for using marijuana in an approved way violates the intention of the law legalizing medical marijuana, it is not certain you'd win; there is considerable uncertainty in this area, and PA's medical marijuana law, like many states' laws, does not do a good job of addressing that marijuana is still otherwise an illegal drug. Rather than putting yourself in that position--possibly being held in violation of parole and having to bring a legal case to *maybe* get that violation overturned--you are better off not using it and sticking with 100% legal drugs or medicines.