You'll note that for now, "I'm Febrifuge, MS, PA." I can say that much because I got my diploma; the MDs who graduated at that same ceremony are MDs as of now, as well. None of us can actually get a license, hospital privileges, or prescription rights until we pass our respective Board exams.
Actually, there's more to it. The MDs have residency spots lined up, which gives them a sort of blanket license to practice in their home hospitals and any affiliated sites. Me, I need to sit for my national certifying exam (which I'm doing later this month), which when passed lets me apply for all that stuff you need to practice.
At that point, having passed the test, I get to be "PA-C" for certified. That's when the fun begins.