No. Or at least not more than $600.
There is something in bankruptcy called a “preferential transfer” where you prefer one creditor over all of the others. It is a bad thing. So, let’s say you pay your doctor on a past due bill of $1,000, then you have preferred him over all of your other creditors. This isn’t fair to the other creditors, and the bankruptcy trustee may sue your doctor to recover the $1,000. There is (kind of) a $600 threshold, but it’s dangerous to pay off unsecured creditors before going bankruptcy.
Today, I had a client with court-ordered therapy. He wanted to pay the therapist on a $1,000 past due bill to continue his therapy so that he was not in violation of parole. Even though it is court ordered, it is still a preferential transfer, and I warned him to not pay more than the $600.
So, to recap: if you pay off your doctor on a past due bill before you go bankruptcy, your doctor may get sued by the bankruptcy trustee.