A PCP referral is the first step. I would hope that he would have some kind of diagnosis insofar as what dept to start with.Once that is done and you have verified that you insurance will be accepted.they will contact you and decide when you should come in for an appointment. They will then send you an itinerary for your visit. If you need to be seen by other depts that should be no problem. I am waiting on a liver transplant but in the interim have developed SCLE. So now I got to dermatology as well. Get every record you can get your hands on and bring them with you! Information helps. I have the utmost confidence that if your problem can be solved, they can solve it. The staff will help you any way they can to walk you through the process. Mayo is NOT like your local county hospital.....