If not interested, why there several recent threads here?

I forgot to mention another feature which I did not know before until recently, reading a forum about how to get insurance for their elderly parents from China.  It turns out it is possible if you meet certain conditions.  You just dont get the SSA side's supplement to make your Part A Free, and Part B a low premium.

Other ways to get Medicare coverage?

If you do not qualify on your own or through your spouse’s work record but are a U.S. citizen or have been a legal resident for at least five years, you can get full Medicare benefits at age 65 or older. You just have to buy into them by:

https://www.aarp.org/health/medicare-insurance/info-04-2011/medicare-eligibility.html

This might be very useful for those who have elderly parents who come to live in US permanently.