The U.S. is also importing a lot of doctors
&&&&&
Sadly, yes. And native-born doctors are retiring or switching to lucrative practices such as cosmetic surgery or ART [Artificial Reproductive Therapies], diminishing the availability of well-qualified doctors in more necessary, (but more-regulated financially by third party payers) areas of practice.
Some of the ones who I know are leaving practice for government jobs at the FDA, etc. No more malpractice lawsuits to worry about, 40 hour work weeks, and still VERY good pay.