Powerful lobbies are surpressing the number of doctors practicing in the US. If a foreign doctor wants to emigrate and practice here they cannot until they pass TOEFL (reasonable) AND finish US-based residencies, of which there are few. I know a Russian dermatologist who has been a receptionist for years because she cannot get ECFMG certification. Some states are wising up and waiving the residencies, but way more need to do it.