I want to have bariatric surgery, and have very good reasons for doing
it, but my health insurance will not pay.  The operation costs about
$20,000.  I am willing to spend $20,000, but the insurance company
says it will not pay for any complications related to this surgery. 
In other words, if I have this routine procedure and something goes
terribly wrong, I could be financially wiped out by medical bills.   I
also don't want the insurance company blaming something else in the
future on this procedure.

How can I protect myself against a financial disaster if something
goes wrong?  If I need some kind of additional one-time "insurance", I
need to know exactly where I can get it from, and about what it will
cost from that source.

Have you considered traveling to India for the procedure? Their prices
are very reasonable, many of the physicians are trained in the US and
UK, and their hospitals are like luxury hotels. Even with airfare it
could cost much less than the procedure in the US!

I am not concerned about the cost of the surgery itself.  My question
has only to to with avoiding medical bankruptcy should I wind up a
vegetable.  Thanks.

I realize that. If there are complications, treating them is cheaper in India.

Look, if you wind up a vegetable you really won't care one whit about
the cost. The problem occurs when there are complications and you need
a third of a million dollars to get patched up.

As procedures in India are about 15-20% or so the US cost, your $20K
could conceivably get you to India, get you the procedure, cover
contingencies and complications, and get you back-- first class (or at
least business).

As an Indian journalist, I would caution you against having bariatric
surgery in India. Here, though medical procedures are usually 10 per
cent of what you would pay in the US or UK, there's also a whole lot
of quacks who will show you all kinds of certificates and offer to do
this type of surgery for a pittance. This is not a procedure that is
very common in India and I wouldn't advise you to come here for this
surgery costs or no. If you have a medical condition requiring this
form of surgery check with your own doctors first whether they can put
you onto a qualified doctor in India who specialises in this form of
surgery. If it is not a medical emergency, dont come to India for this
type of surgery.

sorry one more thing i forgot to suggest is that if it is excess
weight that's causing a problem, you can come to India for a long term
yoga cum ayurveda problem rather than considering surgery as the
option. You may be able to lose the necessary weight through massage
and other help and then consult your own doctor whether you need
surgery thereafter. regards and hope this helps

You can insure against any risk, be it one-time or continuous.  You
could start here: http://www.lloyds.com/   Not that I'm pushing
Lloyd's; they insure through local agents which you can find on the
site.