Holy crap, be prepared to wait and wait and wait. When I go there in the morning had to stand in a line outside the building in 105 degree heat for an hour just to get through security and into the IRS office. Once inside the office you have to get into another line to state what reason you are there for and get a number. Then after that I sat around for another 4 hours waiting for said number to be called. On the plus side everyone that I encountered was very friendly and professional.