When you buy insurance at the EXACT same time you buy the ticket (on AA anyway, not sure about Jet Blue) the price is lower than if you try to buy it later. I had one time that I sure thought I had clicked the box to buy the insurance and it didn't go through. I called the same day and said that I had intended to buy it, claimed it was a computer snafu, and they let me buy it for the same price as before. I honestly don't really know what kind of medical evac is covered with those policies, but it sure is better than nothing..