Megan Mcardle with a fairly simple plan for guaranteed catastrophic cover in place of Dem bill she doesn't like. It is not the same as this idea I have suggested, but they are cousins. Main point of both: federally guaranteed catastrophic cover (she via tax code, me via Medicare), private insurance underneath, with folks purchasing extra cover if they wish with after tax dollars.
And another, from a very famous one that is also a cousin. However, this one seems a bit more complicated and would require new agency.