I suppose when an M.D you have to fund your own retirement. Is there any pension?
Who would pay a physician’s pension? Not only physicians but LOTS of people are having to fund their own retirements these days. My husband put in 23 years with the same employer - a NASDAQ firm with 8000 employees - and will not see any pension money. He did get stock options which we had as part of our retirement portfolio. Since the big market “adjustment” of a few years back, that stock has yet to get back to the level at which we purchased the options. 
the exception being, if you are a physician in government service then you would have a pension, like any other civil servant. i would guess that there are also some systems where docs are employees rather than businesspeople that would have some retirement plan.
private practice is supposed to earn you more money so you can pay for your retirement plan yourself. i don’t know too much about that though; i hope to avoid private practice entirely.
joe