I recommend that since you are paying 'physician rates' to get a procedure like sclerotherapy, that you stick with a Board Certified physician, nurse practitioner or physician assistant. Having said that, each State has its own rules.
The law varies by state, but I would not recommend as sclerotherapy is a more advanced procedure than it may appear, and if you go to a board-certified dermatologist you are more likely to have complete clearance in fewer sessions.