There are a few of us Yanks here working in the NZ medical system. I actually went to school over here so I don't really count as a US physician. But during school and since, I've met probably around 20 or so working in all different fields. Mainly ER, but also internal med, plastics, radiology, OBGYN, neurosurg, etc. I'm sure there is a good few hundred scattered all throughout the north and south island.