One of the major takeaways from this discussion regarding lost luggage is the concept of primary or secondary insurance: With whom do you file a claim for benefits whether it's for lost luggage or a medical claim outside your home area.
When purchasing travel insurance, especially medical insurance, you should be aware if the policy is primary or secondary to your US medical insurance. If it is primary, it will quite often guarantee or pay the deposit required by many foreign hospitals. If it is secondary, you will probably have to post cash bond yourself or accept an immediate charge on your credit card before getting treated in some ports. You will then have to submit the claim to your home medical insurer, get the confirmation of claim denial, and then submit to the travel insurance company for adjudication.
Because of this upfront payment necessity, many people buy travel medical insurance that is primary since these could be quite large and in excess of some people's credit card limit.